Cross Reference to Related Applications
Incorporation of the Sequence Listing
[0002] A sequence listing is contained in the file named "pa_53517.txt" which is 65,000
bytes (measured in MS-Windows) and was created on May 22, 2007 and is located in computer
readable form on a diskette filed herewith and incorporated herein by reference.
Field of the Invention
[0003] The present invention is in the field of plant breeding and disease resistance. More
specifically, the invention relates to a method for screening plants from the genus
Glycine containing quantitative trait loci that are associated with disease resistance and
methods for breeding disease resistant
Glycine plants. The disease can be caused by a fungus, virus, bacterium, or invertebrate
animal. The invention further relates to the use of accession germplasm containing
quantitative trait loci (QTL) conferring disease resistance for introgression into
elite germplasm in a breeding program for resistance to the fungal pathogen,
Phakopsora pachyrhizi.
Background of the Invention
[0005] Soybean yields in the United States are reduced each year by diseases. High yields
per hectare are critical to a farmer's profit margin, especially during periods of
low prices for soybean. The financial loss caused by soybean diseases is important
to rural economies and to the economies of allied industries in urban areas. The effects
of these losses are eventually felt throughout the soybean market worldwide. Estimates
of loss due to disease in the United States and Ontario vary from year to year and
by disease. From 1999 to 2002 soybean yield loss estimates were in the range of 8
million metric tons to 10 million metric tons in the United States and 90,000 to 166,000
metric tons in Ontario (
Wrather et al., Online. Plant Health Progress doi: 10:1094/PHP-2003-0325-01-RV).
[0006] Asian Soybean Rust (herein referred to as ASR) has been reported in the Eastern and
Western Hemispheres. In the Eastern Hemisphere, ASR has been reported in Australia,
China, India, Japan, Taiwan and Thailand. In the Western Hemisphere, ASR has been
observed in Brazil, Columbia, Costa Rica and Puerto Rico. ASR can be a devastating
disease, causing yield losses of up to 70 to 80% as reported in some fields in Taiwan.
Plants that are heavily infected have fewer pods and smaller seeds that are of poor
quality (
Frederick et al., Mycology 92: 217-227 (2002)). ASR was first observed in the United States in Hawaii in 1994. ASR was later introduced
into the continental United States in the fall of 2004, presumably as a consequence
of tropical storm activity. Model predictions indicated that ASR had been widely dispersed
throughout the southeastern United States, and subsequent field and laboratory observations
confirmed this distribution.
[0007] Two species of fungi,
Phakopsora pachyrhizi Sydow and
Phakopsora meibomiae (Arthur) Arthur, cause ASR. Unlike other rusts,
P. pachyrhizi and
P.
meibomiae infect an unusually broad range of plant species.
P. pachyrhizi is known to naturally infect 31 species in 17 genera of legumes and 60 species in
26 other genera have been infected under controlled conditions.
P. meibomiae naturally infects 42 species in 19 genera of legumes, and 18 additional species in
12 other genera have been artificially infected. Twenty-four plant species in 19 genera
are hosts for both species (
Frederick et al., Mycology 92: 217-227 (2002)).
[0008] Soybean plants resistant to ASR have been identified. Four dominant, independently
inherited race-specific QTL for resistance to
P. pachyrhizi, herein designated ASR resistance locus 1, ASR resistance locus 2, ASR resistance
locus 3, and ASR resistance locus 4, have been identified in PI 200492, PI 230970,
PI 462312 (Ankur), and PI 459025B, respectively. These lines, as well as seven others,
are suspected of containing QTL for ASR resistance. PI 239871A and PI 239871B (G.
soja), PI 230971 and PI 459024B, and the cultivars Taita Kaohsiung-5, Tainung-4, and Wayne
have been used as differentials to identify nine races at the Asian Vegetable Research
and Development Center, in Taiwan. The predominant race was compatible with three
or more of the differentials, indicating that some races already possess multiple
virulence factors to known and suspected genes for resistance. Resistance also occurs
among the wild
Glycine spp. from Australia. Rate-reducing resistance has also been demonstrated. However,
it is difficult to evaluate this type of resistance because the rate of rust development
is dependent on soybean development and maturity (
Sinclair et al., eds., Soybean rust workshop. College of Agricultural, Consumer, and
Environmental Sciences. Natl. Soybean Res. Lab. Publ. 1 (1996)).
[0009] Evaluating plants that could potentially contain QTL conferring resistance to ASR
can be time consuming and require large amounts of biologically contained space. Culturing
P. pachyrhizi requires the use of an approved biological containment hood. In addition, greenhouses
and growth chambers used to grow plants for ASR resistance testing will have to be
constructed in a manner that prevents the accidental release of the organism, especially
in locations in which the organism has still not yet been observed. Different cultures
of
P. pachyrhizi may possess different virulence factors. Over time, new strains of
P. pachyrhizi may be introduced into the United States. Therefore, any breeding program designed
to breed resistance into soybean against ASR will need to be able to respond rapidly
to changes in the
P. pachyrhizi population. Also, breeding for soybean crops used in other geographic locations will
require selecting resistance to the specific strains that affect those regions, in
addition to providing those agronomic characteristics that are preferred by these
farmers in that region. Therefore, there is a great need for a rapid, time and cost
efficient high throughput method for screening germplasm resistant to ASR. This method
must not only provide speed and efficiency, but must also be able to be performed
with a minimal amount of space, allowing for the screening of many samples at one
time.
[0010] The present invention provides a method for screening and selecting a soybean plant
comprising QTL for disease resistance.
Summary of the Invention
[0011] The present invention provides a method for assaying soybean plants for disease resistance,
immunity, or susceptibility comprising: (a) detaching a plant tissue from the soybean
plant; (b) cultivating said tissue in a media; (c) exposing said tissue to a plant
pathogen; and (d) assessing said tissue for resistance, immunity, or susceptibility
to disease caused by the pathogen. Additionally, the plant response to the pathogen
can be evaluated by the following steps (e) isolating nucleic acids (DNA and/or RNA)
from said plant; (f) assaying said nucleic acids (DNA, RNA, and/or cDNA) for the presence
of one or more molecular markers for a quantitative trait locus associated with said
resistance, immunity, or susceptibility; and (g) selecting said plant for use in a
breeding program. Determination of resistance, immunity, or susceptibility of a plant
to a particular pathogen is obvious to anyone skilled in the art. The plant tissue
can be leaf, vascular tissue, flower, pod, root, stem, seed, or a portion thereof,
or a cell isolated from the tissue. Exposing said tissue to a plant pathogen is accomplished
by a means selected from the group consisting of (a) direct application of the pathogen
to the tissue; (b) inclusion of the pathogen in the culture media; and (c) inclusion
of an agent that is effectively contaminated with the pathogen and serves to inoculate
the tissue. The plant pathogen can be a fungus, virus, bacterium, or invertebrate
animal. The plant pathogen exposure can be in the form of pathogen macromolecules,
cells, tissues, whole organism or combinations thereof, wherein the pathogen, and
parts thereof, is either living or dead so long that the material mediates an immune
response in the host tissue. Pathogen macromolecules relevant for the present invention
include, but are not limited to, toxins, cell walls or membranes, antigens, and polysaccharides.
[0012] The present invention further comprises a QTL that confers disease resistance to
a fungal pathogen selected from the group consisting of
Phakopsora pachyrhizi, Phakopsora meibomiae (Asian Soybean Rust),
Colletotrichum truncatum, Colletotrichum dematium var.
truncatum, Glomerella glycines (Soybean Anthracnose),
Phytophthora sojae (Phytophthora root and stem rot),
Sclerotinia sclerotiorum (Sclerotinia stem rot),
Fusarium solani f. sp.
glycines (sudden death syndrome),
Fusarium spp. (Fusarium root rot),
Macrophomina phaseolina (charcoal rot),
Septoria glycines, (Brown Spot),
Pythium aphanidermatum, Pythium debaryanum, Pythium irregulare, Pythium ultimum, Pythium
myriotylum, Pythium torulosum (Pythium seed decay),
Diaporthe phaseolorum var. sojae (Pod blight),
Phomopsis longicola (Stem blight),
Phomopsis spp. (Phomopsis seed decay),
Peronospora manshurica (Downy Mildew),
Rhizoctonia solani (Rhizoctonia root and stem rot,Rhizoctonia aerial blight),
Phialophora gregata (Brown Stem Rot),
Diaporthe phaseolorum var.
caulivora (Stem Canker),
Cercospora kikuchii (Purple Seed Stain),
Alternaria sp. (Target Spot),
Cercospora sojina (Frogeye Leafspot),
Sclerotium rolfsii (Southern blight),
Arkoola nigra (Black leaf blight),
Thielaviopsis basicola, (Black root rot),
Choanephora infundibulifera, Choanephora trispora (Choanephora leaf blight),
Leptosphaerulina trifolii (Leptosphaerulina leaf spot),
Mycoleptodiscus terrestris (Mycoleptodiscus root rot),
Neocosmospora vasinfecta (Neocosmospora stem rot),
Phyllosticta sojicola (Phyllosticta leaf spot),
Pyrenochaeta glycines (Pyrenochaeta leaf spot),
Cylindrocladium crotalariae (Red crown rot),
Dactuliochaeta glycines (Red leaf blotch),
Spaceloma glycines (Scab),
Stemphylium botryosum (Stemphylium leaf blight),
Corynespora cassiicola (Target spot),
Nematospora coryli (Yeast spot), and
Phymatotrichum omnivorum (Cotton Root Rot).
[0013] The present invention further comprises a QTL that confers disease resistance to
a viral pathogen selected from the group consisting of
Alfamovirus (Alfafa mosaic virus, AMV),
Comovirus (bean pod mottle virus, BPMV),
Potyvirus (bean yellow mosaic virus, BYMV), Bromovirus (cowpea chlorotic mottle virus, CCMV),
Begomovirus (mung bean yellow mosaivc virus, MYMV),
Potyvirus (peanut mottle virus, PeMoV),
Potyvirus (peanut stripe virus, PStV),
Cucumovirus (peanut stunt virus, PSV),
Caulimovirus (soybean chlorotic mottle virus, SbCMV),
Begomovirus (soybean crinkle leaf virus, SCLV),
Luteovirus (soybean dwarf virus, SbDV),
Potyvirus (soybean mosaic virus, SMV),
Nepovirus (soybean severe stunt virus, SSSV), and
Nepovirus (tobacco ringspot virus, TRSV).
[0014] The present invention further comprises a QTL that confers disease resistance to
a bacterial pathogen selected from the group consisting of
Bacillus subtilis (Bacillus seed decay),
Pseudomonas savastonoi pv.
glycinea (Bacterial blight),
Pseudomonas syringae subsp.
syringae (Bacterial crinkle-leaf),
Xanthomonas axonopodis pv.
glycines, (Bacterial pustule),
Curtobacterium flaccumfaciens pv.
flaccumfaciens, (Bacterial tan spot),
Curtobacterium flaccumfaciens pv.
flaccumfaciens, Ralstonia solanacearum, (Bacterial wilt), and
Pseudomonas syringae pv.
tabaci (Wildfire).
[0015] The present invention further comprises a QTL that confers disease resistance to
a invertebrate pathogen selected from the group consisting of
Aphis glycines (Soybean aphid),
Heterodera glycines (Soybean cyst nematode),
Meloidogyne arenaria, Meloidogyne hapla, Meloidogyne incognita, Meloidogyne javanica (Root knot nematode),
Hoplolaimus Columbus, Hoplolaimus galeatus, Hoplolaimus magnistylus (Lance nematode),
Pratylenchus spp. (Lesion nematode),
Paratylenchus projectus, Paratylenchus tenuicaudatus (Pin nematode),
Rotylenchulus reniformis (Reniform nematode),
Criconemella ornata (Ring nematode),
Hemicycliophora spp. (Sheath nematode),
Heliocotylenchus spp. (Spiral nematode),
Belonolainus gracilis, Belonolainus longicaudatus (Sting nematode),
Quinisulcius acutus, Tylenchorhynchus spp. (Stunt nematode), and
Paratrichodorus minor (Stubby root nematode).
[0016] The present invention also provides selected soybean tissue and plants that are resistant
to
Phakopsora pachyrhizi, Phakopsora meibomiae (Asian Soybean Rust),
Colletotrichum truncatum, Colletotrichum dematium var.
truncatum, Glomerella glycines (Soybean Anthracnose),
Phytophthora sojae (Phytophthora root and stem rot),
Sclerotinia sclerotiorum (Sclerotinia stem rot),
Fusarium solani f. sp.
glycines (sudden death syndrome),
Fusarium spp. (Fusarium root rot),
Macrophomina phaseolina (charcoal rot),
Septoria glycines, (Brown Spot),
Pythium aphanidermatum, Pythium debaryanum, Pythium irregulare, Pythium ultimum, Pythium
myriotylum, Pythium torulosum (Pythium seed decay),
Diaporthe phaseolorum var. sojae (Pod blight),
Phomopsis longicola (Stem blight),
Phomopsis spp. (Phomopsis seed decay),
Peronospora manshurica (Downy Mildew),
Rhizoctonia solani (Rhizoctonia root and stem rot,Rhizoctonia aerial blight),
Phialophora gregata (Brown Stem Rot),
Diaporthe phaseolorum var.
caulivora (Stem Canker),
Cercospora kikuchii (Purple Seed Stain),
Alternaria sp. (Target Spot),
Cercospora sojina (Frogeye Leafspot),
Sclerotium rolfsii (Southern blight),
Arkoola nigra (Black leaf blight),
Thielaviopsis basicola, (Black root rot),
Choanephora infundibulifera, Choanephora trispora (Choanephora leaf blight),
Leptosphaerulina trifolii (Leptosphaerulina leaf spot),
Mycoleptodiscus terrestris (Mycoleptodiscus root rot),
Neocosmospora vasinfecta (Neocosmospora stem rot),
Phyllosticta sojicola (Phyllosticta leaf spot),
Pyrenochaeta glycines (Pyrenochaeta leaf spot),
Cylindrocladium crotalariae (Red crown rot),
Dactuliochaeta glycines (Red leaf blotch),
Spaceloma glycines (Scab),
Stemphylium botryosum (Stemphylium leaf blight),
Corynespora cassiicola (Target spot),
Nematospora coryli (Yeast spot),
Phymatotrichum omnivorum (Cotton Root Rot),
Alfamovirus (Alfafa mosaic virus, AMV),
Comovirus (bean pod mottle virus, BPMV),
Potyvirus (bean yellow mosaic virus, BYMV), Bromovirus (cowpea chlorotic mottle virus, CCMV),
Begomovirus (mung bean yellow mosaivc virus, MYMV),
Potyvirus (peanut mottle virus, PeMoV),
Potyvirus (peanut stripe virus, PStV),
Cucumovirus (peanut stunt virus, PSV),
Caulimovirus (soybean chlorotic mottle virus, SbCMV),
Begomovirus (soybean crinkle leaf virus, SCLV),
Luteovirus (soybean dwarf virus, SbDV),
Potyvirus (soybean mosaic virus, SMV),
Nepovirus (soybean severe stunt virus, SSSV),
Nepovirus (tobacco ringspot virus, TRSV),
Bacillus subtilis (Bacillus seed decay),
Pseudomonas savastonoi pv.
glycinea (Bacterial blight),
Pseudomonas syringae subsp.
syringae (Bacterial crinkle-leaf),
Xanthomonas axonopodis pv.
glycines, (Bacterial pustule),
Curtobacterium flaccumfaciens pv.
flaccumfaciens, (Bacterial tan spot),
Curtobacterium flaccumfaciens pv.
flaccumfaciens, Ralstonia solanacearum, (Bacterial wilt),
Pseudomonas syringae pv.
tabaci (Wildfire),
Aphis glycines (Soybean aphid),
Heterodera glycines (Soybean cyst nematode),
Meloidogyne arenaria, Meloidogyne hapla, Meloidogyne incognita, Meloidogyne javanica (Root knot nematode),
Hoplolaimus Columbus, Hoplolaimus galeatus, Hoplolaimus magnistylus (Lance nematode),
Pratylenchus spp. (Lesion nematode),
Paratylenchus projectus, Paratylenchus tenuicaudatus (Pin nematode),
Rotylenchulus reniformis (Reniform nematode),
Criconemella ornata (Ring nematode),
Hemicycliophora spp. (Sheath nematode),
Heliocotylenchus spp. (Spiral nematode),
Belonolainus gracilis, Belonolainus longicaudatus (Sting nematode),
Quinisulcius acutus, Tylenchorhynchus spp. (Stunt nematode), or
Paratrichodorus minor (Stubby root nematode).
[0017] The present invention further provides that the selected plant is from the group
consisting of members of the genus Glycine, more specifically from the group consisting
of
Glycine arenaria, Glycine argyrea, Glycine canescens, Glycine clandestine, Glycine
curvata, Glycine cyrtoloba, Glycine falcate, Glycine latifolia, Glycine latrobeana,
Glycine max, Glycine microphylla, Glycine pescadrensis, Glycine pindanica, Glycine
rubiginosa, Glycine soja, Glycine sp., Glycine stenophita, Glycine tabacina and
Glycine tomentella.
[0018] The present invention further provides that the media used in the method for selection
is comprised of water that is untreated, distilled or deionized. The media can contain
any ingredients necessary to sustain the pathogen or plant tissue, so long as the
ingredients do not interfere with the expression of resistance as conferred by the
QTL.
[0019] The present invention further provides a soybean plant selected using said method.
[0020] The present invention also provides a QTL that is selected from the group consisting
of
Phytophthora (root rot) infection tolerance locus,
Fusarium solani f. sp.
glycines (sudden death syndrome) resistance locus,
Cercospora sojina (Frogeye leaf spot) resistance locus,
Phialophora gegata (brown stem rot) resistance locus,
Sclerotinia (stem rot) resistance locus, ASR resistance locus 1, ASR resistance locus 2, ASR
resistance locus 3, ASR resistance locus 4, ASR resistance locus 5, ASR resistance
locus 6, ASR resistance locus 7, ASR resistance locus 8, ASR resistance locus 9, ASR
resistance locus 10, ASR resistance locus 11, ASR resistance locus 12, and ASR resistance
locus 13.
[0021] The present invention further provides that the selected plant contains one or more
fungal disease resistance QTL, including ASR resistance locus 1, ASR resistance locus
2, ASR resistance locus 3, ASR resistance locus 4, ASR resistance locus 5, ASR resistance
locus 6, ASR resistance locus 7, ASR resistance locus 8, ASR resistance locus 9, ASR
resistance locus 10, ASR resistance locus 11, ASR resistance locus 12, and ASR resistance
locus 13.
[0022] The present invention further provides one or more single nucleotide polymorphism
(SNP) marker loci for ASR resistance locus 1, wherein said SNP marker is selected
from the group consisting of NS0093250, NS0119710, NS0103004, NS0099454, NS0102630,
NS0102915, NS0102913, NS0123728, NS0129943, NS0102168, NS0092723, NS0098177, NS0127343,
and NS0101121. One or more SNP marker loci for ASR resistance locus 3 are also provided,
wherein said SNP marker is selected from the group consisting of NS0099746, NS0123747,
NS0126598, NS0128378, NS0096829, NS0125408, NS0098902, NS0099529, NS0097798, NS0137477,
NS0095322, NS0136101, and NS0098982. An exemplary SNP marker locus, NS0103033, is
provided for ASR resistance locus 5, ASR resistance locus 6, ASR resistance locus
7, ASR resistance locus 8, and ASR resistance locus 9. Another exemplary SNP marker
locus, NS0124935, is provided for ASR resistance locus 10, ASR resistance locus 11,
ASR resistance locus 12, and ASR resistance locus 13. Further, one or more markers
mapped within 10 centimorgans or less from said marker molecules can be used for the
selection and introgression of ASR resistance loci.
[0023] The present invention further provides a method for selecting and introgressing ASR
resistance in soybean comprising: (a) isolating nucleic acids from a plurality of
soybean plants; (b) detecting in said isolated nucleic acids the presence of one or
more marker molecules associated with ASR resistance loci 1-13, wherein said marker
molecule is selected from the group consisting of SEQ ID NOs: 67 through 99, and any
one marker molecule mapped within 10 centimorgans or less from said marker molecules;
and (c) selecting a soybean plant comprising said one or more marker molecules, thereby
selecting an ASR resistant soybean plant.
[0024] The present invention further provides for a soybean plant selected using said method.
Detailed Description Of The Invention
[0025] The present invention provides a method for screening soybean plants for resistance,
immunity, or susceptibility to a fungal disease. In a preferred embodiment the plant
is selected from the genus
Glycine. The wild perennial soybeans belong to the subgenus
Glycine and have a wide array of genetic diversity. The cultivated soybean (
Glycine max (L.) Merr.) and its wild annual progenitor (
Glycine soja (Sieb. and Zucc.)) belong to the subgenus
Soja, contain 2n = 40 chromosomes, are cross-compatible, usually produce vigorous fertile
F1 hybrids, and carry similar genomes. Crosses between cultivated
Glycine species and wild perennial
Glycine species are possible, the success of which is variable amongst accessions. Investigations
have shown that several wild perennial
Glycine accessions carry resistance to brown spot, soybean rust, root rot, yellow mosaic
virus, and powdery mildew. There are more than 100,000
Glycine max accessions, probably less than 10,000
Glycine soja accessions and approximately, 3500 accessions of perennial
Glycine species in germplasm collections throughout the world. The exact numbers are unknown.
Major
Glycine collections exist in Australia, Brazil, China, Germany, India, Indonesia, Japan,
Russia, South Korea, and the United States. Many other smaller but important collections
exist throughout Asia and Europe. It is not known how many of the accessions are duplicated
among collections. The USDA Soybean Germplasm Collection is one of the largest collections
and the largest outside Asia (
Verma et al., eds., Soybean: Genetics, Molecular Biology and Biotechnology (1996)). It currently contains 20,765 accessions, comprised of 19 species collections,
including 18,680 accessions of
Glycine max and 1,166 accessions of
Glycine soja as well as perennial
Glycine species.
[0026] In a preferred embodiment, a soybean plant is assayed for disease resistance, immunity,
or susceptibility comprising: (a) detaching a plant tissue from the soybean plant;
(b) cultivating said tissue in a media; (c) exposing said tissue to a plant pathogen;
and (d) assessing said tissue for resistance, immunity, or susceptibility to disease
caused by the pathogen. Additionally, the plant response to the pathogen can be evaluated
by the following steps (e) isolating nucleic acids from said plant; (f) assaying said
nucleic acids for the presence of one or more molecular markers for a quantitative
trait locus associated with said resistance, immunity, or susceptibility; and (g)
selecting said plant for use in a breeding program. Determination of resistance, immunity,
or susceptibility of a plant to a particular pathogen is obvious to anyone skilled
in the art. The plant tissue can be leaf, vascular tissue, flower, pod, root, stem,
seed, or a portion thereof, or a cell isolated from the tissue. Exposing said tissue
to a plant pathogen is accomplished by a means selected from the group consisting
of (a) direct application of the pathogen to the tissue; (b) inclusion of the pathogen
in the culture media; and (c) inclusion of an agent that is effectively contaminated
with the pathogen and serves to inoculate the tissue. The plant pathogen can be a
fungus, virus, bacterium, or invertebrate animal. The plant pathogen exposure can
be in the form of pathogen macromolecules, cells, tissues, whole organism or combinations
thereof, wherein the pathogen, and parts thereof, is either living or dead so long
that the material mediates an immune response in the host tissue. Pathogen macromolecules
relevant for the present invention include, but are not limited to, toxins, cell walls
or membranes, antigens, and polysaccharides.
[0027] In a preferred embodiment, the leaf tissue may comprise a cotyledon leaf, unifoliate
leaf, a trifoliate leaf, and prophylls. There are four types of soybean leaves: 1)
the first pair of simple cotyledons or seed leaves, 2) second pair of simple primary
leaves, also known as unifoliate leaves, 3) trifoliate foliage leaves, and 4) prophylls,
which are plant parts resembling leaves. The unifoliate leaves occur at the first
node above the cotyledons. All other leaves would be trifoliates, wherein the first
pair to emerge following the unifoliates are the first trifoliate leaves, which are
followed by the emergence of the second trifoliates leaves and then the third trifoliate
leaves (
H.R. Boerma and J.E. Specht (ed.) Soybean Monograph, 3rd Edition, Am. Soc. Agron.,
Madison, WI (2004)).
[0028] In a preferred embodiment, the present invention enables a soybean plant to be assayed
for resistance, immunity, or susceptibility to a fungal disease. Soybean diseases
caused by fungi include, but are not limited to,
Phakopsora pachyrhizi, Phakopsora meibomiae (Asian Soybean Rust),
Colletotrichum truncatum, Colletotrichum dematium var.
truncatum, Glomerella glycines (Soybean Anthracnose),
Phytophthora sojae (Phytophthora root and stem rot),
Sclerotinia sclerotiorum (Sclerotinia stem rot),
Fusarium solani f. sp.
glycines (sudden death syndrome),
Fusarium spp. (Fusarium root rot),
Macrophomina phaseolina (charcoal rot),
Septoria glycines, (Brown Spot),
Pythium aphanidermatum, Pythium debaryanum, Pythium irregulare, Pythium ultimum, Pythium
myriotylum, Pythium torulosum (Pythium seed decay),
Diaporthe phaseolorum var. sojae (Pod blight),
Phomopsis longicola (Stem blight),
Phomopsis spp. (Phomopsis seed decay),
Peronospora manshurica (Downy Mildew),
Rhizoctonia solani (Rhizoctonia root and stem rot,Rhizoctonia aerial blight),
Phialophora gregata (Brown Stem Rot),
Diaporthe phaseolorum var.
caulivora (Stem Canker),
Cercospora kikuchii (Purple Seed Stain),
Alternaria sp. (Target Spot),
Cercospora sojina (Frogeye Leafspot),
Sclerotium rolfsii (Southern blight),
Arkoola nigra (Black leaf blight),
Thielaviopsis basicola, (Black root rot),
Choanephora infundibulifera, Choanephora trispora (Choanephora leaf blight),
Leptosphaerulina trifolii (Leptosphaerulina leaf spot),
Mycoleptodiscus terrestris (Mycoleptodiscus root rot),
Neocosmospora vasinfecta (Neocosmospora stem rot),
Phyllosticta sojicola (Phyllosticta leaf spot),
Pyrenochaeta glycines (Pyrenochaeta leaf spot),
Cylindrocladium crotalariae (Red crown rot),
Dactuliochaeta glycines (Red leaf blotch),
Spaceloma glycines (Scab),
Stemphylium botryosum (Stemphylium leaf blight),
Corynespora cassiicola (Target spot),
Nematospora coryli (Yeast spot), and
Phymatotrichum omnivorum (Cotton Root Rot).
[0029] In a preferred embodiment, the present invention enables a soybean plant to be assayed
for resistance, immunity, or susceptibility to a viral disease. Soybean diseases caused
by viruses include, but are not limited to,
Alfamovirus (Alfafa mosaic virus, AMV),
Comovirus (bean pod mottle virus, BPMV),
Potyvirus (bean yellow mosaic virus, BYMV), Bromovirus (cowpea chlorotic mottle virus, CCMV),
Begomovirus (mung bean yellow mosaivc virus, MYMV),
Potyvirus (peanut mottle virus, PeMoV),
Potyvirus (peanut stripe virus, PStV),
Cucumovirus (peanut stunt virus, PSV),
Caulimovirus (soybean chlorotic mottle virus, SbCMV),
Begomovirus (soybean crinkle leaf virus, SCLV),
Luteovirus (soybean dwarf virus, SbDV),
Potyvirus (soybean mosaic virus, SMV),
Nepovirus (soybean severe stunt virus, SSSV), and
Nepovirus (tobacco ringspot virus, TRSV).
[0030] In a preferred embodiment, the present invention enables a soybean plant to be assayed
for resistance, immunity, or susceptibility to a bacterial disease. Soybean diseases
caused by bacteria include, but are not limited to,
Bacillus subtilis (Bacillus seed decay),
Pseudomonas savastonoi pv.
glycinea (Bacterial blight),
Pseudomonas syringae subsp.
syringae (Bacterial crinkle-leaf),
Xanthomonas axonopodis pv.
glycines, (Bacterial pustule),
Curtobacterium flaccumfaciens pv.
flaccumfaciens, (Bacterial tan spot),
Curtobacterium flaccumfaciens pv.
flaccumfaciens, Ralstonia solanacearum, (Bacterial wilt), and
Pseudomonas syringae pv.
tabaci (Wildfire).
[0031] In a preferred embodiment, the present invention enables a soybean plant to be assayed
for resistance, immunity, or susceptibility to an animal pest disease. Soybean diseases
caused by animal pests include, but are not limited to
Aphis glycines (Soybean aphid),
Heterodera glycines (Soybean cyst nematode),
Meloidogyne arenaria, Meloidogyne hapla, Meloidogyne incognita, Meloidogyne javanica (Root knot nematode),
Hoplolaimus Columbus, Hoplolaimus galeatus, Hoplolaimus magnistylus (Lance nematode),
Pratylenchus spp. (Lesion nematode),
Paratylenchus projectus, Paratylenchus tenuicaudatus (Pin nematode),
Rotylenchulus reniformis (Reniform nematode),
Criconemella ornata (Ring nematode),
Hemicycliophora spp. (Sheath nematode),
Heliocotylenchus spp. (Spiral nematode),
Belonolainus gracilis, Belonolainus longicaudatus (Sting nematode),
Quinisulcius acutus, Tylenchorhynchus spp. (Stunt nematode), and
Paratrichodorus minor (Stubby root nematode).
[0032] The invention further provides a method for selection and introgression of QTL for
disease resistance in soybean comprising: (a) isolating nucleic acids from a plurality
of soybean plants; (b) detecting in said isolated nucleic acids the presence of one
or more marker molecules associated with disease resistance QTL; and (c) selecting
a soybean plant comprising said one or more marker molecules, thereby selecting a
disease resistant soybean plant.
[0033] The disease resistance QTL of the present invention may be introduced into an elite
Glycine max line. An "elite line" is any line that has resulted from breeding and selection for
superior agronomic performance. Examples of elite lines are lines that are commercially
available to farmers or soybean breeders such as HARTZ™ variety H4994, HARTZ™ variety
H5218, HARTZ™ variety H5350, HARTZ™ variety H5545, HARTZ™ variety H5050, HARTZ™ variety
H5454, HARTZ™ variety H5233, HARTZ™ variety H5488, HARTZ™ variety HLA572, HARTZ™ variety
H6200, HARTZ™ variety H6104, HARTZ™ variety H6255, HARTZ™ variety H6586, HARTZ™ variety
H6191, HARTZ™ variety H7440, HARTZ™ variety H4452 Roundup Ready™, HARTZ™ variety H4994
Roundup Ready™, HARTZ™ variety H4988 Roundup Ready™, HARTZ™ variety H5000 Roundup
Ready™, HARTZ™ variety H5147 Roundup Ready™, HARTZ™ variety H5247 Roundup Ready™,
HARTZ™ variety H5350 Roundup Ready™, HARTZ™ variety H5545 Roundup Ready™, HARTZ™ variety
H5855 Roundup Ready™, HARTZ™ variety H5088 Roundup Ready™, HARTZ™ variety H5164 Roundup
Ready™, HARTZ™ variety H5361 Roundup Ready™, HARTZ™ variety H5566 Roundup Ready™,
HARTZ™ variety H5181 Roundup Ready™, HARTZ™ variety H5889 Roundup Ready™, HARTZ™ variety
H5999 Roundup Ready™, HARTZ™ variety H6013 Roundup Ready™, HARTZ™ variety H6255 Roundup
Ready™, HARTZ™ variety H6454 Roundup Ready™, HARTZ™ variety H6686 Roundup Ready™,
HARTZ™ variety H7152 Roundup Ready™, HARTZ™ variety H7550 Roundup Ready™, HARTZ™ variety
H8001 Roundup Ready™ (HARTZ SEED, Stuttgart, Arkansas, USA); A0868, AG0202, AG0401,
AG0803, AG0901, A1553, A1900, AG1502, AG1702, AG1901, A1923, A2069, AG2101, AG2201,
AG2205, A2247, AG2301, A2304, A2396, AG2401, AG2501, A2506, A2553, AG2701, AG2702,
AG2703, A2704, A2833, A2869, AG2901, AG2902, AG2905, AG3001, AG3002, AG3101, A3204,
A3237, A3244, AG3301, AG3302, AG3006, AG3203, A3404, A3469, AG3502, AG3503, AG3505,
AG3305, AG3602, AG3802, AG3905, AG3906, AG4102, AG4201, AG4403, AG4502, AG4603, AG4801,
AG4902, AG4903, AG5301, AG5501, AG5605, AG5903, AG5905 A3559, AG3601, AG3701, AG3704,
AG3750, A3834, AG3901, A3904, A4045 AG4301, A4341, AG4401, AG4404, AG4501, AG4503,
AG4601, AG4602, A4604, AG4702, AG4703, AG4901, A4922, AG5401, A5547, AG5602, AG5702,
A5704, AG5801, AG5901, A5944, A5959, AG6101, AJW2600C0R, FPG26932, QR4459 and QP4544
(Asgrow Seeds, Des Moines, Iowa, USA); DKB26-52, DKB28-51, DKB32-52, DKB08-51, DKB09-53,
DKB10-52, DKB18-51, DKB26-53, DKB29-51, DKB42-51, DKB35-51 DKB34-51, DKB36-52, DKB37-51,
DKB38-52, DKB46-51, DKB54-52 and DeKalb variety CX445 (DeKalb, Illinois, USA); 91B91,
92B24, 92B37, 92B63, 92B71, 92B74, 92B75, 92B91, 93B01, 93B11, 93B26, 93B34, 93B35,
93B41, 93B45, 93B51, 93B53, 93B66, 93B81, 93B82, 93B84, 94B01, 94B32, 94B53, 94M80
RR, 94M50 RR, 95B71, 95B95, 95M81 RR, 95M50 RR, 95M30 RR, 9306, 9294, 93M50, 93M93,
94B73, 94B74, 94M41, 94M70, 94M90, 95B32, 95B42, 95B43 and 9344 (Pioneer Hi-bred International,
Johnston, Iowa, USA); SSC-251RR, SSC-273CNRR, AGRA 5429RR, SSC-314RR, SSC-315RR, SSC-311STS,
SSC-320RR, AGRA5432RR, SSC-345RR, SSC-356RR, SSC-366, SSC-373RR and AGRA5537CNRR (Schlessman
Seed Company, Milan, Ohio, USA); 39-E9, 44-R4, 44-R5, 47-G7, 49-P9, 52-Q2, 53-K3,
56-J6, 58-V8, ARX A48104, ARX B48104, ARX B55104 and GP530 (Armor Beans, Fisher, Arkansas,
USA); HT322STS, HT3596STS, L0332, L0717, L1309CN, L1817, L1913CN, L1984, L2303CN,
L2495, L2509CN, L2719CN, L3997CN, L4317CN, RC1303, RC1620, RC1799, RC1802, RC1900,
RC1919, RC2020, RC2300, RC2389, RC2424, RC2462, RC2500, RC2504, RC2525, RC2702, RC2964,
RC3212, RC3335, RC3354, RC3422, RC3624, RC3636, RC3732, RC3838, RC3864, RC3939, RC3942,
RC3964, RC4013, RC4104, RC4233, RC4432, RC4444, RC4464, RC4842, RC4848, RC4992, RC5003,
RC5222, RC5332, RC5454, RC5555, RC5892, RC5972, RC6767, RC7402, RT0032, RT0041, RT0065,
RT0073, RT0079, RT0255, RT0269, RT0273, RT0312, RT0374, RT0396, RT0476, RT0574, RT0583,
RT0662, RT0669, RT0676, RT0684, RT0755, RT0874, RT0907, RT0929, RT0994, RT0995, RT1004,
RT 1183, RT 1199, RT 1234, RT 1399, RT 1413, RT1535, RT1606, RT1741, RT1789, RT1992,
RT2000, RT2041, RT2089, RT2092, RT2112, RT2127, RT2200, RT2292, RT2341, RT2430, RT2440,
RT2512, RT2544, RT2629, RT2678, RT2732, RT2800, RT2802, RT2822, RT2898, RT2963, RT3176,
RT3200, RT3253, RT3432, RT3595, RT3836, RT4098, RX2540, RX2944, RX3444 and TS466RR
(Croplan Genetics, Clinton, Kentucky, USA); 4340RR, 4630RR, 4840RR, 4860RR, 4960RR,
4970RR, 5260RR, 5460RR, 5555RR, 5630RR and 5702RR (Delta Grow, England, Arkansas,
USA); DK3964RR, DK3968RR, DK4461RR, DK4763RR, DK4868RR, DK4967RR, DK5161RR, DK5366RR,
DK5465RR, DK55T6, DK5668RR, DK5767RR, DK5967RR, DKXTJ446, DKXTJ448, DKXTJ541, DKXTJ542,
DKXTJ543, DKXTJ546, DKXTJ548, DKXTJ549, DKXTJ54J9, DKXTJ54X9, DKXTJ554, DKXTJ555,
DKXTJ55J5 and DKXTJ5K57 (Delta King Seed Company, McCrory, Arkansas, USA); DP 3861RR,
DP 4331 RR, DP 4546RR, DP 4724 RR, DP 4933 RR, DP 5414RR, DP 5634 RR, DP 5915 RR,
DPX 3950RR, DPX 4891RR, DPX 5808RR (Delta & Pine Land Company, Lubbock, Texas, USA);
DG31T31, DG32C38, DG3362NRR, DG3390NRR, DG33A37, DG33B52, DG3443NRR, DG3463NRR, DG3481NRR,
DG3484NRR, DG3535NRR, DG3562NRR, DG3583NRR, DG35B40, DG35D33, DG36M49, DG37N43, DG38K57,
DG38T47, SX04334, SX04453 (Dyna-gro line, UAP-MidSouth, Cordova, Tennessee, USA);
8374RR CYSTX, 8390 NNRR, 8416RR, 8492NRR and 8499NRR (Excel Brand, Camp Point, Illinois,
USA); 4922RR, 5033RR, 5225RR and 5663RR (FFR Seed, Southhaven, Mississippi, USA);
3624RR/N, 3824RR/N, 4212RR/N, 4612RR/N, 5012RR/N, 5212RR/N and 5412RR/STS/N (Garst
Seed Company, Slater, Iowa, USA); 471, 4R451, 4R485, 4R495, 4RS421 and 5R531 (Gateway
Seed Company, Nashville, Illinois, USA); H-3606RR, H-3945RR, H-4368RR, H-4749RR, H-5053RR
and H-5492RR (Golden Harvest Seeds, Inc., Pekin, Illinois, USA); HBK 5324, HBK 5524,
HBK R4023, HBK R4623, HBK R4724, HBK R4820, HBK R4924, HBK R4945CX, HBK R5620 and
HBK R5624 (Hornbeck Seed Co. Inc., DeWitt, Arkansas, USA); 341 RR/SCN, 343 RR/SCN,
346 RR/SCN, 349 RR, 355 RR/SCN, 363 RR/SCN, 373 RR, 375 RR, 379 RR/SCN, 379+ RR/SCN,
380 RR/SCN, 380+ RR/SCN, 381 RR/SCN, 389 RR/SCN, 389+ RR/SCN, 393 RR/SCN, 393+ RR/SCN,
398 RR, 402 RR/SCN, 404 RR, 424 RR, 434 RR/SCN and 442 RR/SCN (Kruger Seed Company,
Dike, Iowa, USA); 3566, 3715, 3875, 3944, 4010 and 4106 (Lewis Hybrids, Inc., Ursa,
Illinois, USA); C3999NRR (LG Seeds, Elmwood, Illinois, USA); Atlanta 543, Austin RR,
Cleveland VIIRR, Dallas RR, Denver RRSTS, Everest RR, Grant 3RR, Olympus RR, Phoenix
IIIRR, Rocky RR, Rushmore 553RR and Washington IXRR (Merschman Seed Inc., West Point,
Iowa, USA); RT 3304N, RT 3603N, RT 3644N, RT 3712N, RT 3804N, RT 3883N, RT 3991N,
RT 4044N, RT 4114N, RT 4124N, RT 4201N, RT 4334N, RT 4402N, RT 4480N, RT 4503N, RT
4683N, RT 4993N, RT 5043N, RT 5204, RT 5553N, RT 5773, RT4731N and RTS 4824N (MFA
Inc., Columbia, Missouri, USA); 9A373NRR, 9A375XRR, 9A385NRS, 9A402NRR, 9A455NRR,
9A485XRR and 9B445NRS (Midland Genetics Group L.L.C., Ottawa, Kansas, USA); 3605nRR,
3805nRR, 3903nRR, 3905nRR, 4305nRR, 4404nRR, 4705nRR, 4805nRR, 4904nRR, 4905nRR, 5504nRR
and 5505nRR (Midwest Premium Genetics, Concordia, Missouri, USA); S37-N4, S39-K6,
S40-R9, S42-P7, S43-B1, S49-Q9, S50-N3, S52-U3 and S56-D7 (Syngenta Seeds, Henderson,
Kentucky, USA); NT-3707 RR, NT-3737 RR/SCN, NT-3737+RR/SCN, NT-3737sc RR/SCN, NT-3777+
RR, NT-3787 RR/SCN, NT-3828 RR, NT-3839 RR, NT-3909 RR/SCN/STS, NT-3909+ RR/SCN/ST,
NT-3909sc RR/SCN/S, NT-3919 RR, NT-3922 RR/SCN, NT-3929 RR/SCN, NT-3999 RR/SCN, NT-3999+
RR/SCN, NT-3999sc RR/SCN, NT-4040 RR/SCN, NT-4040+ RR/SCN, NT-4044 RR/SCN, NT-4122
RR/SCN, NT-4414 RR/SCN/STS, NT-4646 RR/SCN and NT-4747 RR/SCN (NuTech Seed Co., Ames,
Iowa, USA); PB-3494NRR, PB-3732RR, PB-3894NRR, PB-3921NRR, PB-4023NRR, PB-4394NRR,
PB-4483NRR and PB-5083NRR (Prairie Brand Seed Co., Story City, Iowa, USA); 3900RR,
4401RR, 4703RR, 4860RR, 4910, 4949RR, 5250RR, 5404RR, 5503RR, 5660RR, 5703RR, 5770,
5822RR, PGY 4304RR, PGY 4604RR, PGY 4804RR, PGY 5622RR and PGY 5714RR (Progeny Ag
Products, Wynne, Arkansas, USA); R3595RCX, R3684Rcn, R3814RR, R4095Rcn, R4385Rcn and
R4695Rcn (Renze Hybrids Inc., Carroll, Iowa, USA); S3532-4, S3600-4, S3832-4, S3932-4,
S3942-4, S4102-4, S4542-4 and S4842-4 (Stine Seed Co., Adel, Iowa, USA); 374RR, 398RRS
(Taylor Seed Farms Inc., White Cloud, Kansas, USA); USG 5002T, USG 510nRR, USG 5601T,
USG 7440nRR, USG 7443nRR, USG 7473nRR, USG 7482nRR, USG 7484nRR, USG 7499nRR, USG
7504nRR, USG 7514nRR, USG 7523nRR, USG 7553nRS and USG 7563nRR (UniSouth Genetics
Inc., Nashville, Tennessee, USA); V38N5RS, V39N4RR, V42N3RR, V48N5RR, V284RR, V28N5RR,
V315RR, V35N4RR, V36N5RR, V37N3RR, V40N3RR, V47N3RR, and V562NRR (Royster-Clark Inc.,
Washington C.H., Ohio, USA); RR2383N, 2525NA, RR2335N, RR2354N, RR2355N, RR2362, RR2385N,
RR2392N, RR2392NA, RR2393N, RR2432N, RR2432NA, RR2445N, RR2474N, RR2484N, RR2495N
and RR2525N (Willcross Seed, King City Seed, King City, Missouri, USA); 1493RR, 1991NRR,
2217RR, 2301NRR, 2319RR, 2321NRR, 2341NRR, 2531NRR, 2541NRR, 2574RR, 2659RR, 2663RR,
2665NRR, 2671NRR, 2678RR, 2685RR, 2765NRR, 2782NRR, 2788NRR, 2791NRR, 3410RR, 3411NRR,
3419NRR, 3421NRR, 3425NRR, 3453NRR, 3461NRR, 3470CRR, 3471NRR, 3473NRR, 3475RR, 3479NRR,
3491NRR, 3499NRR, WX134, WX137, WX177 and WX300 (Wilken Seeds, Pontiac, Illinois,
USA). An elite plant is a representative plant from an elite line.
[0034] The disease resistance QTL of the present invention may also be introduced into an
elite
Glycine max transgenic plant that contains one or more genes for herbicide tolerance, increased
yield, insect control, fungal disease resistance, virus resistance, nematode resistance,
bacterial disease resistance, mycoplasma disease resistance, modified oils production,
high oil production, high protein production, germination and seedling growth control,
enhanced animal and human nutrition, low raffinose, environmental stress resistant,
increased digestibility, industrial enzymes, pharmaceutical proteins, peptides and
small molecules, improved processing traits, improved flavor, nitrogen fixation, hybrid
seed production, reduced allergenicity, biopolymers, and biofuels among others. These
agronomic traits can be provided by the methods of plant biotechnology as transgenes
in
Glycine max.
[0036] The disease resistant effect of the QTL can vary based on the parental genotype and
on the environmental conditions in which the disease resistance effect is measured.
It is within the skill of those in the art of plant breeding and without undue experimentation
to use the methods described herein to select from a population of plants or from
a collection of parental genotypes those that when containing a disease locus result
in enhanced disease resistance relative to the parent genotype. Herein, a plant disease
can be caused by a fungi, virus, bacterium or invertebrate animal.
[0037] A number of molecular genetic maps of
Glycine have been reported (
Mansur et al., Crop Sci. 36: 1327-1336 (1996),
Shoemaker et al., Genetics 144: 329-338 (1996),
Shoemaker et al., Crop Science 32: 1091-1098 (1992),
Shoemaker et al., Crop Science 35: 436-446 (1995),
Tinley et al.,, J. Cell Biochem. Suppl. 14E: 291 (1990),
Cregan et al., Crop Science 39:1464-1490 (1999)).
Glycine max, Glycine soja and
Glycine max x.
Glycine soja share linkage groups (
Shoemaker et al., Genetics 144: 329-338 (1996)). As used herein, reference to the linkage groups, G; C2; J; and N of
Glycine max refers to the linkage group that corresponds to linkage groups, G; C2; J; and N from
the genetic map of
Glycine max (
Mansur et al., Crop Science. 36: 1327-1336 (1996),
Cregan et al., Crop Science 39:1464-1490 (1999), and Soybase, Agricultural Research Service, United States Department of Agriculture).
[0038] An allele of a QTL can, of course, comprise multiple genes or other genetic factors
even within a contiguous genomic region or linkage group, such as a haplotype. As
used herein, an allele of a QTL can therefore encompasses more than one gene or other
genetic factor where each individual gene or genetic component is also capable of
exhibiting allelic variation and where each gene or genetic factor is also capable
of eliciting a phenotypic effect on the quantitative trait in question. In an embodiment
of the present invention the allele of a QTL comprises one or more genes or other
genetic factors that are also capable of exhibiting allelic variation. The use of
the term "an allele of a QTL" is thus not intended to exclude a QTL that comprises
more than one gene or other genetic factor. Specifically, an "allele of a QTL" in
the present in the invention can denote a haplotype within a haplotype window wherein
a phenotype can be disease resistance. A haplotype window is a contiguous genomic
region that can be defined, and tracked, with a set of one or more polymorphic markers
wherein said polymorphisms indicate identity by descent. A haplotype within that window
can be defined by the unique fingerprint of alleles at each marker. As used herein,
an allele is one of several alternative forms of a gene occupying a given locus on
a chromosome. When all the alleles present at a given locus on a chromosome are the
same, that plant is homozygous at that locus. If the alleles present at a given locus
on a chromosome differ, that plant is heterozygous at that locus.
[0039] Plants of the present invention can be part of or generated from a breeding program.
The choice of breeding method depends on the mode of plant reproduction, the heritability
of the trait(s) being improved, and the type of cultivar used commercially (e.g.,
F
1 hybrid cultivar, pureline cultivar, etc.). A cultivar is a race or variety of a plant
that has been created or selected intentionally and maintained through cultivation.
[0040] Selected, non-limiting approaches for breeding the plants of the present invention
are set forth below. A breeding program can be enhanced using marker assisted selection
(MAS) of the progeny of any cross. It is further understood that any commercial and
non-commercial cultivars can be utilized in a breeding program. Factors such as, for
example, emergence vigor, vegetative vigor, stress tolerance, disease resistance,
branching, flowering, seed set, seed size, seed density, standability, and threshability
etc. will generally dictate the choice.
[0041] For highly heritable traits, a choice of superior individual plants evaluated at
a single location will be effective, whereas for traits with low heritability, selection
should be based on mean values obtained from replicated evaluations of families of
related plants. Popular selection methods commonly include pedigree selection, modified
pedigree selection, mass selection, and recurrent selection. In a preferred embodiment
a backcross or recurrent breeding program is undertaken.
[0042] The complexity of inheritance influences choice of the breeding method. Backcross
breeding can be used to transfer one or a few favorable genes for a highly heritable
trait into a desirable cultivar. This approach has been used extensively for breeding
disease-resistant cultivars. Various recurrent selection techniques are used to improve
quantitatively inherited traits controlled by numerous genes. The use of recurrent
selection in self-pollinating crops depends on the ease of pollination, the frequency
of successful hybrids from each pollination event, and the number of hybrid offspring
from each successful cross.
[0043] Breeding lines can be tested and compared to appropriate standards in environments
representative of the commercial target area(s) for two or more generations. The best
lines are candidates for new commercial cultivars; those still deficient in traits
may be used as parents to produce new populations for further selection.
[0044] One method of identifying a superior plant is to observe its performance relative
to other experimental plants and to a widely grown standard cultivar. If a single
observation is inconclusive, replicated observations can provide a better estimate
of its genetic worth. A breeder can select and cross two or more parental lines, followed
by repeated selfing and selection, producing many new genetic combinations.
[0045] The development of new soybean cultivars requires the development and selection of
soybean varieties, the crossing of these varieties and selection of superior hybrid
crosses. The hybrid seed can be produced by manual crosses between selected male-fertile
parents or by using male sterility systems. Hybrids are selected for certain single
gene traits such as pod color, flower color, seed yield, pubescence color or herbicide
resistance which indicate that the seed is truly a hybrid. Additional data on parental
lines, as well as the phenotype of the hybrid, influence the breeder's decision whether
to continue with the specific hybrid cross.
[0046] Pedigree breeding and recurrent selection breeding methods can be used to develop
cultivars from breeding populations. Breeding programs combine desirable traits from
two or more cultivars or various broad-based sources into breeding pools from which
cultivars are developed by selfing and selection of desired phenotypes. New cultivars
can be evaluated to determine which have commercial potential.
[0047] Pedigree breeding is used commonly for the improvement of self-pollinating crops.
Two parents who possess favorable, complementary traits are crossed to produce an
F
1. An F
2 population is produced by selfing one or several F
1's. Selection of the best individuals in the best families is selected. Replicated
testing of families can begin in the F
4 generation to improve the effectiveness of selection for traits with low heritability.
At an advanced stage of inbreeding (i.e., F
6 and F
7), the best lines or mixtures of phenotypically similar lines are tested for potential
release as new cultivars.
[0048] Backcross breeding has been used to transfer genes for a simply inherited, highly
heritable trait into a desirable homozygous cultivar or inbred line, which is the
recurrent parent. The source of the trait to be transferred is called the donor parent.
The resulting plant is expected to have the attributes of the recurrent parent (e.g.,
cultivar) and the desirable trait transferred from the donor parent. After the initial
cross, individuals possessing the phenotype of the donor parent are selected and repeatedly
crossed (backcrossed) to the recurrent parent. The resulting parent is expected to
have the attributes of the recurrent parent (e.g., cultivar) and the desirable trait
transferred from the donor parent.
[0049] The single-seed descent procedure in the strict sense refers to planting a segregating
population, harvesting a sample of one seed per plant, and using the one-seed sample
to plant the next generation. When the population has been advanced from the F
2 to the desired level of inbreeding, the plants from which lines are derived will
each trace to different F
2 individuals. The number of plants in a population declines each generation due to
failure of some seeds to germinate or some plants to produce at least one seed. As
a result, not all of the F
2 plants originally sampled in the population will be represented by a progeny when
generation advance is completed.
[0050] In a multiple-seed procedure, soybean breeders commonly harvest one or more pods
from each plant in a population and thresh them together to form a bulk. Part of the
bulk is used to plant the next generation and part is put in reserve. The procedure
has been referred to as modified single-seed descent or the pod-bulk technique.
[0051] The multiple-seed procedure has been used to save labor at harvest. It is considerably
faster to thresh pods with a machine than to remove one seed from each by hand for
the single-seed procedure. The multiple-seed procedure also makes it possible to plant
the same number of seed of a population each generation of inbreeding.
[0053] The present invention also provides for parts of the plants of the present invention.
Plant parts, without limitation, include seed, endosperm, ovule and pollen. In a particularly
preferred embodiment of the present invention, the plant part is a seed.
[0054] Plants or parts thereof of the present invention may be grown in culture and regenerated.
Methods for the regeneration of
Glycine max plants from various tissue types and methods for the tissue culture of
Glycine max are known in the art (See, for example,
Widholm et al., In Vitro Selection and Culture-induced Variation in Soybean, In Soybean:
Genetics, Molecular Biology and Biotechnology, eds. Verma and Shoemaker, CAB International,
Wallingford, Oxon, England (1996)). Regeneration techniques for plants such as
Glycine max can use as the starting material a variety of tissue or cell types. With
Glycine max in particular, regeneration processes have been developed that begin with certain
differentiated tissue types such as meristems (
Cartha et al., Can. J. Bot. 59:1671-1679 (1981)), hypocotyl sections (
Cameya et al., Plant Science Letters 21: 289-294 (1981)), and stem node segments
(Saka et al., Plant Science Letters, 19: 193-201 (1980),
Cheng et al., Plant Science Letters, 19: 91-99 (1980)). Regeneration of whole sexually mature
Glycine max plants from somatic embryos generated from explants of immature
Glycine max embryos has been reported (
Ranch et al., In Vitro Cellular & Developmental Biology 21: 653-658 (1985)). Regeneration of mature
Glycine max plants from tissue culture by organogenesis and embryogenesis has also been reported
(
Barwale et al., Planta 167: 473-481 (1986),
Wright et al., Plant Cell Reports 5: 150-154 (1986)).
[0055] The present invention also provides a disease resistant soybean plant selected for
by screening for disease resistance, immunity, or susceptibility in the soybean plant,
the selection comprising interrogating genomic nucleic acids for the presence of a
marker molecule that is genetically linked to an allele of a QTL associated with disease
resistance in the soybean plant, where the allele of a QTL is also located on a linkage
group associated with disease resistant soybean. The disease can be caused by a fungus,
virus, bacterium, or invertebrate animal.
[0056] The present invention also provides for QTL conferring resistance to Asian Soybean
Rust, including ASR resistance locus 1, ASR resistance locus 2, ASR resistance locus
3, ASR resistance locus 4, ASR resistance locus 5, ASR resistance locus 6, ASR resistance
locus 7, ASR resistance locus 8, ASR resistance locus 9, ASR resistance locus 10,
ASR resistance locus 11, ASR resistance locus 12, and ASR resistance locus 13. Four
dominant and independently inherited loci for resistance to
P. pachyrhizi, herein designated ASR resistance locus 1 through 4, have been identified in PI 200492,
PI 230970, PI 462312 (Ankur), and PI 459025B, respectively. In the present invention,
ASR resistance locus 1 has been localized to linkage group G of soybean. SNP markers
used to monitor the introgression of ASR resistance locus 1 are selected from the
group consisting of NS0093250, NS0119710, NS0103004, NS0099454, NS0102630, NS0102915,
NS0102913, NS0123728, NS0129943, NS0102168, NS0092723, NS0098177, NS0127343 and NS0101121.
The ASR resistance locus 1 SNP marker DNA sequences (presented as SEQ ID NOs: 67 through
80) can be amplified using the primers indicated as SEQ ID NOs: 1 through 28 and detected
with probes indicated as SEQ ID NOs: 100 through 127. In the present invention, ASR
resistance locus 2 is most likely located on linkage group J, near or within the disease
resistance cluster containing Brown Stem Rot, Soybean Cyst Nematode resistance and
Frog Eye Leaf Spot resistance; or linkage group N. In the present invention, ASR resistance
locus 3 is localized to linkage group C2. SNP markers used to monitor the introgression
of ASR resistance locus 3 are selected from the group consisting of NS0099746, NS0123747,
NS0126598, NS0128378, NS0096829, NS0125408, NS0098902, NS0099529, NS0097798, NS0137477,
NS0095322, NS0136101, NS0098982, NS0103749, NS0118897, NS0119715, and NS0130920. These
marker DNA sequences (presented as SEQ ID NOs:81 through 97) can be amplified using
the primers indicated as SEQ ID NOs: 29 through 62 and detected with probes indicated
as SEQ ID NOs: 128 through 161. In the present invention, ASR resistance locus 4 is
likely located on linkage group N.
[0057] The present invention also provides for haplotypes that confer resistance to ASR
that were identified in association studies. These genome-wide surveys revealed two
SNP markers associated with ASR resistance located in two different windows on chromosome
13. In the first haplotype window, the SNP marker used to monitor he introgression
of ASR resistance locus 5, ASR resistance locus 6, ASR resistance locus 7, ASR resistance
locus 8, and ASR resistance locus 9 is NS0103033. This SNP marker DNA sequences (presented
as SEQ ID NO: 98) can be amplified using the primers indicated as SEQ ID NOs: 63 and
64 and detected with probes indicated as SEQ ID NOs: 162 and 163. In the second haplotype
window, the SNP marker used to monitor the introgression of ASR resistance locus 10,
ASR resistance locus 11, ASR resistance locus 12, and ASR resistance locus 13 is NS0124935.
This SNP marker DNA sequences (presented as SEQ ID NO: 99) can be amplified using
the primers indicated as SEQ ID NOs: 65 and 66 and detected with probes indicated
as SEQ ID NOs: 164 and 165.
[0058] It is further understood, that one or more markers mapped within 10 centimorgans
or less from said marker molecules can be used for the selection and introgression
of ASR resistance loci.
[0059] It is further understood, that the present invention provides bacterial, viral, microbial,
insect, mammalian and plant cells comprising the agents of the present invention.
[0060] Nucleic acid molecules or fragments thereof are capable of specifically hybridizing
to other nucleic acid molecules under certain circumstances. As used herein, two nucleic
acid molecules are capable of specifically hybridizing to one another if the two molecules
are capable of forming an anti-parallel, double-stranded nucleic acid structure. A
nucleic acid molecule is the "complement" of another nucleic acid molecule if they
exhibit complete complementarity. As used herein, molecules are exhibit "complete
complementarity" when every nucleotide of one of the molecules is complementary to
a nucleotide of the other. Two molecules are "minimally complementary" if they can
hybridize to one another with sufficient stability to permit them to remain annealed
to one another under at least conventional "low-stringency" conditions. Similarly,
the molecules are "complementary" if they can hybridize to one another with sufficient
stability to permit them to remain annealed to one another under conventional "high-stringency"
conditions. Conventional stringency conditions are described by
Sambrook et al., In: Molecular Cloning, A Laboratory Manual, 2nd Edition, Cold Spring
Harbor Press, Cold Spring Harbor, New York (1989), and by
Haymes et al., In: Nucleic Acid Hybridization, A Practical Approach, IRL Press, Washington,
DC (1985). Departures from complete complementarity are therefore permissible, as long as
such departures do not completely preclude the capacity of the molecules to form a
double-stranded structure. In order for a nucleic acid molecule to serve as a primer
or probe it need only be sufficiently complementary in sequence to be able to form
a stable double-stranded structure under the particular solvent and salt concentrations
employed.
[0061] As used herein, a substantially homologous sequence is a nucleic acid sequence that
will specifically hybridize to the complement of the nucleic acid sequence to which
it is being compared under high stringency conditions. The nucleic-acid probes and
primers of the present invention can hybridize under stringent conditions to a target
DNA sequence. The term "stringent hybridization conditions" is defined as conditions
under which a probe or primer hybridizes specifically with a target sequence(s) and
not with non-target sequences, as can be determined empirically. The term "stringent
conditions" is functionally defined with regard to the hybridization of a nucleic-acid
probe to a target nucleic acid (i.e., to a particular nucleic-acid sequence of interest)
by the specific hybridization procedure discussed in Sambrook
et al., 1989, at 9.52-9.55. See also,
Sambrook et al., (1989) at 9.47-9.52, 9.56-9.58,
Kanehisa Nucl. Acids Res. 12:203-213, (1984), and
Wetmur et al., J. Mol. Biol. 31:349-370 (1968). Appropriate stringency conditions that promote DNA hybridization are, for example,
6.0 x sodium chloride/sodium citrate (SSC) at about 45° C, followed by a wash of 2.0
x SSC at 50°C, are known to those skilled in the art or can be found in
Current Protocols in Molecular Biology, John Wiley & Sons, N.Y., 1989, 6.3.1-6.3.6. For example, the salt concentration in the wash step can be selected from a low
stringency of about 2.0 x SSC at 50°C to a high stringency of about 0.2 x SSC at 50°C.
In addition, the temperature in the wash step can be increased from low stringency
conditions at room temperature, about 22°C, to high stringency conditions at about
65°C. Both temperature and salt may be varied, or either the temperature or the salt
concentration may be held constant while the other variable is changed.
[0062] For example, hybridization using DNA or RNA probes or primers can be performed at
65°C in 6x SSC, 0.5% SDS, 5x Denhardt's, 100 µg/mL nonspecific DNA (e.g., sonicated
salmon sperm DNA) with washing at 0.5x SSC, 0.5% SDS at 65°C, for high stringency.
[0063] It is contemplated that lower stringency hybridization conditions such as lower hybridization
and/or washing temperatures can be used to identify related sequences having a lower
degree of sequence similarity if specificity of binding of the probe or primer to
target sequence(s) is preserved. Accordingly, the nucleotide sequences of the present
invention can be used for their ability to selectively form duplex molecules with
complementary stretches of DNA, RNA, or cDNA fragments. Detection of DNA segments
via hybridization is well-known to those of skill in the art, and thus depending on
the application envisioned, one will desire to employ varying hybridization conditions
to achieve varying degrees of selectivity of probe towards target sequence and the
method of choice will depend on the desired results.
[0064] As used herein, an agent, be it a naturally occurring molecule or otherwise may be
"substantially purified", if desired, referring to a molecule separated from substantially
all other molecules normally associated with it in its native state. More preferably
a substantially purified molecule is the predominant species present in a preparation.
A substantially purified molecule may be greater than 60% free, preferably 75% free,
more preferably 90% free, and most preferably 95% free from the other molecules (exclusive
of solvent) present in the natural mixture. The term "substantially purified" is not
intended to encompass molecules present in their native state.
[0065] The agents of the present invention will preferably be "biologically active" with
respect to either a structural attribute, such as the capacity of a nucleic acid to
hybridize to another nucleic acid molecule, or the ability of a protein to be bound
by an antibody (or to compete with another molecule for such binding). Alternatively,
such an attribute may be catalytic, and thus involve the capacity of the agent to
mediate a chemical reaction or response.
[0066] The agents of the present invention may also be recombinant. As used herein, the
term recombinant means any agent (e.g. DNA, peptide etc.), that is, or results, however
indirect, from human manipulation of a nucleic acid molecule.
[0067] The agents of the present invention may be labeled with reagents that facilitate
detection of the agent (e.g. fluorescent labels (
Prober et al., Science 238:336-340 (1987), European Patent
144914), chemical labels (
U.S. Patent 4,582,789,
U.S. Patent 4,563,417), modified bases (European Patent
119448), all of which are herein incorporated by reference in their entirety).
[0068] In a preferred embodiment, a nucleic acid of the present invention will specifically
hybridize to one or more of the nucleic acid molecules set forth in SEQ ID NO: 67
through SEQ ID NO: 99 or complements thereof or fragments of either under moderately
stringent conditions, for example at about 2.0 x SSC and about 65°C. In a particularly
preferred embodiment, a nucleic acid of the present invention will specifically hybridize
to one or more of the nucleic acid molecules set forth in SEQ ID NO: 67 through SEQ
ID NO: 99 or complements or fragments of either under high stringency conditions.
In one aspect of the present invention, a preferred marker nucleic acid molecule of
the present invention has the nucleic acid sequence set forth in SEQ ID NO: 67 through
SEQ ID NO: 99 or complements thereof or fragments of either. In another aspect of
the present invention, a preferred marker nucleic acid molecule of the present invention
shares between 80% and 100% or 90% and 100% sequence identity with the nucleic acid
sequence set forth in SEQ ID NO: 67 through SEQ ID NO: 99 or complement thereof or
fragments of either. In a further aspect of the present invention, a preferred marker
nucleic acid molecule of the present invention shares between 95% and 100% sequence
identity with the sequence set forth in SEQ ID NO: 67 through SEQ ID NO: 99 or complement
thereof or fragments of either. In a more preferred aspect of the present invention,
a preferred marker nucleic acid molecule of the present invention shares between 98%
and 100% sequence identity with the nucleic acid sequence set forth in SEQ ID NO:
67 through SEQ ID NO: 99 or complement thereof or fragments of either.
[0069] Additional genetic markers can be used to select plants with an allele of a QTL associated
with fungal disease resistance of soybean of the present invention. Examples of public
marker databases include, for example: Soybase, an Agricultural Research Service,
United States Department of Agriculture.
[0070] Genetic markers of the present invention include "dominant" or "codominant" markers.
"Codominant markers" reveal the presence of two or more alleles (two per diploid individual).
"Dominant markers" reveal the presence of only a single allele. The presence of the
dominant marker phenotype (e.g., a band of DNA) is an indication that one allele is
present in either the homozygous or heterozygous condition. The absence of the dominant
marker phenotype (e.g., absence of a DNA band) is merely evidence that "some other"
undefined allele is present. In the case of populations where individuals are predominantly
homozygous and loci are predominantly dimorphic, dominant and codominant markers can
be equally valuable. As populations become more heterozygous and multiallelic, codominant
markers often become more informative of the genotype than dominant markers.
[0071] Markers, such as simple sequence repeat markers (SSR), AFLP markers, RFLP markers,
RAPD markers, phenotypic markers, SNPs, isozyme markers, microarray transcription
profiles that are genetically linked to or correlated with alleles of a QTL of the
present invention can be utilized (
Walton, Seed World 22-29 (July, 1993),
Burow et al., Molecular Dissection of Complex Traits, 13-29, ed. Paterson, CRC Press,
New York (1988)). Methods to isolate such markers are known in the art. For example, locus-specific
SSR markers can be obtained by screening a genomic library for microsatellite repeats,
sequencing of "positive" clones, designing primers which flank the repeats, and amplifying
genomic DNA with these primers. The size of the resulting amplification products can
vary by integral numbers of the basic repeat unit. To detect a polymorphism, PCR products
can be radiolabeled, separated on denaturing polyacrylamide gels, and detected by
autoradiography. Fragments with size differences >4 bp can also be resolved on agarose
gels, thus avoiding radioactivity.
[0072] The detection of polymorphic sites in a sample of DNA, RNA, or cDNA may be facilitated
through the use of nucleic acid amplification methods. Such methods specifically increase
the concentration of polynucleotides that span the polymorphic site, or include that
site and sequences located either distal or proximal to it. Such amplified molecules
can be readily detected by gel electrophoresis or other means.
[0073] The most preferred method of achieving such amplification employs the polymerase
chain reaction (PCR) (
Mullis et al., Cold Spring Harbor Symp. Quant. Biol. 51:263-273 (1986),European Patent Appln.
50,424, European Patent
84,796, European Patent
258,017, European Patent
237,362, European Patent
201,184,
U.S. Patent 4,683,202,
U.S. Patent 4,582,788,
U.S. Patent 4,683,194), using primer pairs that are capable of hybridizing to the proximal sequences that
define a polymorphism in its double-stranded form.
[0074] In lieu of PCR, alternative methods, such as the "Ligase Chain Reaction" (LCR) may
be used (
Barany, Proc. Natl. Acad. Sci. (U.S.A.) 88:189-193 (1991), the entirety of which is herein incorporated by reference). LCR uses two pairs
of oligonucleotide probes to exponentially amplify a specific target. The sequence
of each pair of oligonucleotides is selected to permit the pair to hybridize to abutting
sequences of the same strand of the target. Such hybridization forms a substrate for
a template-dependent ligase. As with PCR, the resulting products thus serve as a template
in subsequent cycles and an exponential amplification of the desired sequence is obtained.
[0075] The "Oligonucleotide Ligation Assay" (OLA) may alternatively be employed (
Landegren et al., Science 241:1077-1080 (1988), the entirety of which is herein incorporated by reference). The OLA protocol uses
two oligonucleotides that are designed to be capable of hybridizing to abutting sequences
of a single strand of a target. OLA, like LCR, is particularly suited for the detection
of point mutations. Unlike LCR, however, OLA results in "linear" rather than exponential
amplification of the target sequence.
[0076] Schemes based on ligation of two (or more) oligonucleotides in the presence of a
nucleic acid having the sequence of the resulting "di-oligonucleotide", thereby amplifying
the di-oligonucleotide, are also known (
Wu et al., Genomics 4:560-569 (1989), the entirety of which is herein incorporated by reference), and may be readily
adapted to the purposes of the present invention.
[0077] Other known nucleic acid amplification procedures, such as allele-specific oligomers,
branched DNA technology, transcription-based amplification systems, or isothermal
amplification methods may also be used to amplify and analyze such polymorphisms (
U.S. Patent 5,130,238, European Patent
329,822,
U.S. Patent 5,169,766, European Patent
359,789,
Kwoh, et al., Proc. Natl. Acad. Sci. (U.S.A.) 86:1173-1177 (1989) European Patent
368,906,
Walker et al., Proc. Natl. Acad. Sci. (U.S.A.) 89:392-396 (1992), all of which are herein incorporated by reference in their entirety).
[0078] Polymorphisms can also be identified by Single Strand Conformation Polymorphism (SSCP)
analysis. SSCP is a method capable of identifying most sequence variations in a single
strand of DNA, typically between 150 and 250 nucleotides in length (
Elles, Methods in Molecular Medicine: Molecular Diagnosis of Genetic Diseases, Humana
Press (1996);
Orita et al., Genomics 5: 874-879 (1989)). Under denaturing conditions a single strand of DNA will adopt a conformation that
is uniquely dependent on its sequence conformation. This conformation usually will
be different, even if only a single base is changed. Most conformations have been
reported to alter the physical configuration or size sufficiently to be detectable
by electrophoresis.
[0079] A central attribute of SNPs is that the site of the polymorphism is at a single nucleotide.
SNPs are more stable than other classes of polymorphisms. Their spontaneous mutation
rate is approximately 10
-9 (
Kornberg, DNA Replication, W. H. Freeman & Co., San Francisco (1980)). As SNPs result from sequence variation, new polymorphisms can be identified by
sequencing random genomic or cDNA molecules. SNPs can also result from deletions,
point mutations and insertions. That said, SNPs are also advantageous as markers since
they are often diagnostic of "identity by descent" because they rarely arise from
independent origins. Any single base alteration, whatever the cause, can be a SNP.
SNPs occur at a greater frequency than other classes of polymorphisms and can be more
readily identified. In the present invention, a SNP can represent a single indel event,
which may consist of one or more base pairs, or a single nucleotide polymorphism.
[0080] SNPs can be characterized using any of a variety of methods. Such methods include
the direct or indirect sequencing of the site, the use of restriction enzymes where
the respective alleles of the site create or destroy a restriction site, the use of
allele-specific hybridization probes, the use of antibodies that are specific for
the proteins encoded by the different alleles of the polymorphism, or by other biochemical
interpretation. SNPs can be sequenced using a variation of the chain termination method
(
Sanger et al., Proc. Natl. Acad. Sci. (U.S.A.) 74: 5463-5467 (1977)) in which the use of radioisotopes are replaced with fluorescently-labeled dideoxy
nucleotides and subjected to capillary based automated sequencing (
U.S. Patent 5,332,666, the entirety of which is herein incorporated by reference;
U.S. Patent 5,821,058, the entirety of which is herein incorporated by reference). Automated sequencers
are available from, for example, Applied Biosystems, Foster City, CA (3730xl DNA Analyzer),
Beckman Coulter, Fullerton, CA (CEQ™ 8000 Genetic Analysis System) and LI-COR, Inc.,
Lincoln, NE (4300 DNA Analysis System).
[0081] Approaches for analyzing SNPs can be categorized into two groups. The first group
is based on primer-extension assays, such as solid-phase minisequencing or pyrosequencing.
In the solid-phase minisequencing method, a DNA polymerase is used specifically to
extend a primer that anneals immediately adjacent to the variant nucleotide. A single
labeled nucleoside triphospate complementary to the nucleotide at the variant site
is used in the extension reaction. Only those sequences that contain the nucleotide
at the variant site will be extended by the polymerase. A primer array can be fixed
to a solid support wherein each primer is contained in four small wells, each well
being used for one of the four nucleoside triphospates present in DNA. Template DNA
or RNA from each test organism is put into each well and allowed to anneal to the
primer. The primer is then extended one nucleotide using a polymerase and a labeled
di-deoxy nucleotide triphosphate. The completed reaction can be imaged using devices
that are capable of detecting the label which can be radioactive or fluorescent. Using
this method several different SNPs can be visualized and detected (
Syvänen et al., Hum. Mutat. 13: 1-10 (1999)). The pyrosequencing technique is based on an indirect bioluminometric assay of
the pyrophosphate (PPi) that is released from each dNTP upon DNA chain elongation.
Following Klenow polymerase mediated base incorporation, PPi is released and used
as a substrate, together with adenosine 5-phosphosulfate (APS), for ATP sulfurylase,
which results in the formation of ATP. Subsequently, the ATP accomplishes the conversion
of luciferin to its oxi-derivative by the action of luciferase. The ensuing light
output becomes proportional to the number of added bases, up to about four bases.
To allow processivity of the method dNTP excess is degraded by apyrase, which is also
present in the starting reaction mixture, so that only dNTPs are added to the template
during the sequencing procedure (
Alderborn et al., Genome Res. 10: 1249-1258 (2000)). An example of an instrument designed to detect and interpret the pyrosequencing
reaction is available from Biotage, Charlottesville, VA (PyroMark MD).
[0082] A more recent SNP detection method, based on primer-extension assays is the GOOD
assay. The GOOD assay (
Sauer et al., Nucleic Acids Res. 28: e100 (2000)) is an allele-specific primer extension protocol that employs MALDI-TOF (matrix-assisted
laser desorption/ionization time-of-flight) mass spectrometry. The region of DNA containing
a SNP is amplified first by PCR amplification. Residual dNTPs are destroyed using
an alkaline phosphatase. Allele-specific products are then generated using a specific
primer, a conditioned set of a-S-dNTPs and a-S-ddNTPs and a fresh DNA polymerase in
a primer extension reaction. Unmodified DNA is removed by 5'phosphodiesterase digestion
and the modified products are alkylated to increase the detection sensitivity in the
mass spectrometric analysis. All steps are carried out in a single vial at the lowest
practical sample volume and require no purification. The extended reaction can be
given a positive or negative charge and is detected using mass spectrometry (
Sauer et al., Nucleic Acids Res. 28: e 13 (2000)). An instrument in which the GOOD assay is analyzed is for example, the autoflex®
MALDI-TOF system from Bruker Daltonics (Billerica, MA).
[0083] The second group, which is based on recognition of heteroduplex DNA molecules, includes
oligonucleotide hybridization, Taq-Man assays, molecular beacons, electronic dot blot
assays and denaturing high-performance liquid chromatography. Oligonucleotide hybridizations
can be performed in mass using micro-arrays (
Southern, Trends Genet. 12: 110-115 (1996)). Taq-Man ® assays, or Real Time PCR, detects the accumulation of a specific PCR
product by hybridization and cleavage of a double-labeled fluorogenic probe during
the amplification reaction. A Taq-Man assay includes four oligonucleotides, two of
which serve as PCR primers and generate a PCR product encompassing the polymorphism
to be detected. The other two are allele-specific fluorescence-resonance-energy-transfer
(FRET) probes. FRET probes incorporate a fluorophore and a quencher molecule in close
proximity so that the fluorescence of the fluorophore is quenched. The signal from
a FRET probes is generated by degradation of the FRET oligonucleotide, so that the
fluorophore is released from proximity to the quencher, and is thus able to emit light
when excited at an appropriate wavelength. In the assay, two FRET probes bearing different
fluorescent reporter dyes are used, where a unique dye is incorporated into an oligonucleotide
that can anneal with high specificity to only one of the two alleles. Useful reporter
dyes include 6-carboxy-4,7,2',7'-tetrachlorofluorecein (TET), 2'-chloro-7'-phenyl-1,4-dichloro-6-carboxyfluorescein
(VIC) and 6-carboxyfluorescein phosphoramidite (FAM). A useful quencher is 6-carboxy-N,N,N',N'-tetramethylrhodamine
(TAMRA). Annealed (but not non-annealed) FRET probes are degraded by TAQ DNA polymerase
as the enzyme encounters the 5' end of the annealed probe, thus releasing the fluorophore
from proximity to its quencher. Following the PCR reaction, the fluorescence of each
of the two fluorescers, as well as that of the passive reference, is determined fluorometrically.
The normalized intensity of fluorescence for each of the two dyes will be proportional
to the amounts of each allele initially present in the sample, and thus the genotype
of the sample can be inferred. An example of an instrument used to detect the fluorescence
signal in Taq-Man ® assays, or Real Time PCR are the 7500 Real-Time PCR System (Applied
Biosystems, Foster City, CA).
[0084] Molecular beacons are oligonucleotide probes that form a stem-and-loop structure
and possess an internally quenched fluorophore. When they bind to complementary targets,
they undergo a conformational transition that turns on their fluorescence. These probes
recognize their targets with higher specificity than linear probes and can easily
discriminate targets that differ from one another by a single nucleotide. The loop
portion of the molecule serves as a probe sequence that is complementary to a target
nucleic acid. The stem is formed by the annealing of the two complementary arm sequences
that are on either side of the probe sequence. A fluorescent moiety is attached to
the end of one arm and a nonfluorescent quenching moiety is attached to the end of
the other arm. The stem hybrid keeps the fluorophore and the quencher so close to
each other that the fluorescence does not occur. When the molecular beacon encounters
a target sequence, it forms a probe-target hybrid that is stronger and more stable
than the stem hybrid. The probe undergoes spontaneous conformational reorganization
that forces the arm sequences apart, separating the fluorophore from the quencher,
and permitting the fluorophore to fluoresce (Bonnet et al., 1999). The power of molecular
beacons lies in their ability to hybridize only to target sequences that are perfectly
complementary to the probe sequence, hence permitting detection of single base differences
(
Kota et al., Plant Mol. Biol. Rep. 17: 363-370 (1999)). Molecular beacon detection can be performed for example, on the Mx4000® Multiplex
Quantitative PCR System from Stratagene (La Jolla, CA).
[0085] The electronic dot blot assay uses a semiconductor microchip comprised of an array
of microelectrodes covered by an agarose permeation layer containing streptavidin.
Biotinylated amplicons are applied to the chip and electrophoresed to selected pads
by positive bias direct current, where they remain embedded through interaction with
streptavidin in the permeation layer. The DNA at each pad is then hybridized to mixtures
of fluorescently labeled allele-specific oligonucleotides. Single base pair mismatched
probes can then be preferentially denatured by reversing the charge polarity at individual
pads with increasing amperage. The array is imaged using a digital camera and the
fluorescence quantified as the amperage is ramped to completion. The fluorescence
intensity is then determined by averaging the pixel count values over a region of
interest (
Gilles et al., Nature Biotech. 17: 365-370 (1999)).
[0086] A more recent application based on recognition of heteroduplex DNA molecules uses
denaturing high-performance liquid chromatography (DHPLC). This technique represents
a highly sensitive and fully automated assay that incorporates a Peltier-cooled 96-well
autosampler for high-throughput SNP analysis. It is based on an ion-pair reversed-phase
high performance liquid chromoatography method. The heart of the assay is a polystyrene-divinylbenzene
copolymer, which functions as a stationary phase. The mobile phase is composed of
an ion-pairing agent, triethylammonium acetate (TEAA) buffer, which mediates the binding
of DNA to the stationary phase, and an organic agent, acetonitrile (ACN), to achieve
subsequent separation of the DNA from the column. A linear gradient of CAN allows
the separation of fragments based on the presence of heteroduplexes. DHPLC thus identifies
mutations and polymorphisms that cause heteroduplex formation between mismatched nucleotides
in double-stranded PCR-amplified DNA. In a typical assay, sequence variation creates
a mixed population of heteroduplexes and homoduplexes during reannealing of wild-type
and mutant DNA. When this mixed population is analyzed by DHPLC under partially denaturing
temperatures, the heteroduplex molecules elute from the column prior to the homoduplex
molecules, because of their reduced melting temperatures (
Kota et al., Genome 44: 523-528 (2001)). An example of an instrument used to analyze SNPs by DHPLC is the WAVE® HS System
from Transgenomic, Inc. (Omaha, NE).
[0087] A microarray-based method for high-throughput monitoring of plant gene expression
can be utilized as a genetic marker system. This 'chip'-based approach involves using
microarrays of nucleic acid molecules as gene-specific hybridization targets to quantitatively
or qualitatively measure expression of plant genes (
Schena et al., Science 270:467-470 (1995), the entirety of which is herein incorporated by reference;
Shalon, Ph.D. Thesis. Stanford University (1996), the entirety of which is herein incorporated by reference). Every nucleotide in
a large sequence can be queried at the same time. Hybridization can be used to efficiently
analyze nucleotide sequences. Such microarrays can be probed with any combination
of nucleic acid molecules. Particularly preferred combinations of nucleic acid molecules
to be used as probes include a population of mRNA molecules from a known tissue type
or a known developmental stage or a plant subject to a known stress (environmental
or man-made) or any combination thereof (e.g. mRNA made from water stressed leaves
at the 2 leaf stage). Expression profiles generated by this method can be utilized
as markers.
[0088] For the purpose of QTL mapping, the markers included must be diagnostic of origin
in order for inferences to be made about subsequent populations. SNP markers are ideal
for mapping because the likelihood that a particular SNP allele is derived from independent
origins in the extant populations of a particular species is very low. As such, SNP
markers are useful for tracking and assisting introgression of QTLs, particularly
in the case of haplotypes.
[0089] The genetic linkage of additional marker molecules can be established by a gene mapping
model such as, without limitation, the flanking marker model reported by
Lander and Botstein, Genetics, 121:185-199 (1989), and the interval mapping, based on maximum likelihood methods described by
Lander and Botstein, Genetics, 121:185-199 (1989), and implemented in the software package MAPMAKER/QTL (
Lincoln and Lander, Mapping Genes Controlling Quantitative Traits Using MAPMAKER/QTL,
Whitehead Institute for Biomedical Research, Massachusetts, (1990). Additional software includes Qgene, Version 2.23 (1996), Department of Plant Breeding
and Biometry, 266 Emerson Hall, Cornell University, Ithaca, NY, the manual of which
is herein incorporated by reference in its entirety). Use of Qgene software is a particularly
preferred approach.
[0090] A maximum likelihood estimate (MLE) for the presence of a marker is calculated, together
with an MLE assuming no QTL effect, to avoid false positives. A log
10 of an odds ratio (LOD) is then calculated as: LOD = log
10 (MLE for the presence of a QTL/MLE given no linked QTL). The LOD score essentially
indicates how much more likely the data are to have arisen assuming the presence of
a QTL versus in its absence. The LOD threshold value for avoiding a false positive
with a given confidence, say 95%, depends on the number of markers and the length
of the genome. Graphs indicating LOD thresholds are set forth in
Lander and Botstein, Genetics, 121:185-199 (1989), and further described by
Arús and Moreno-González, Plant Breeding, Hayward, Bosemark, Romagosa (eds.) Chapman
& Hall, London, pp. 314-331 (1993).
[0091] Additional models can be used. Many modifications and alternative approaches to interval
mapping have been reported, including the use of non-parametric methods (
Kruglyak and Lander, Genetics, 139:1421-1428 (1995), the entirety of which is herein incorporated by reference). Multiple regression
methods or models can be also be used, in which the trait is regressed on a large
number of markers (
Jansen, Biometrics in Plant Breed, van Oijen, Jansen (eds.) Proceedings of the Ninth
Meeting of the Eucarpia Section Biometrics in Plant Breeding, The Netherlands, pp.
116-124 (1994);
Weber and Wricke, Advances in Plant Breeding, Blackwell, Berlin, 16 (1994)). Procedures combining interval mapping with regression analysis, whereby the phenotype
is regressed onto a single putative QTL at a given marker interval, and at the same
time onto a number of markers that serve as 'cofactors,' have been reported by
Jansen and Stam, Genetics, 136:1447-1455 (1994) and
Zeng, Genetics, 136:1457-1468 (1994). Generally, the use of cofactors reduces the bias and sampling error of the estimated
QTL positions (
Utz and Melchinger, Biometrics in Plant Breeding, van Oijen, Jansen (eds.) Proceedings
of the Ninth Meeting of the Eucarpia Section Biometrics in Plant Breeding, The Netherlands,
pp. 195-204 (1994), thereby improving the precision and efficiency of QTL mapping (
Zeng, Genetics, 136:1457-1468 (1994)). These models can be extended to multi-environment experiments to analyze genotype-environment
interactions (
Jansen et al., Theo. Appl. Genet. 91:33-37 (1995).
[0092] Selection of appropriate mapping populations is important to map construction. The
choice of an appropriate mapping population depends on the type of marker systems
employed (
Tanksley et al., Molecular mapping of plant chromosomes. chromosome structure and
function: Impact of new concepts J.P. Gustafson and R. Appels (eds.). Plenum Press,
New York, pp. 157-173 (1988), the entirety of which is herein incorporated by reference). Consideration must
be given to the source of parents (adapted vs. exotic) used in the mapping population.
Chromosome pairing and recombination rates can be severely disturbed (suppressed)
in wide crosses (adapted x exotic) and generally yield greatly reduced linkage distances.
Wide crosses will usually provide segregating populations with a relatively large
array of polymorphisms when compared to progeny in a narrow cross (adapted x adapted).
An F
2 population is the first generation of selfing after the hybrid seed is produced.
Usually a single F
1 plant is selfed to generate a population segregating for all the genes in Mendelian
(1:2:1) fashion. Maximum genetic information is obtained from a completely classified
F
2 population using a codominant marker system (
Mather, Measurement of Linkage in Heredity: Methuen and Co., (1938), the entirety of which is herein incorporated by reference). In the case of dominant
markers, progeny tests (e.g F
3, BCF
2) are required to identify the heterozygotes, thus making it equivalent to a completely
classified F
2 population. However, this procedure is often prohibitive because of the cost and
time involved in progeny testing. Progeny testing of F
2 individuals is often used in map construction where phenotypes do not consistently
reflect genotype (e.g. disease resistance) or where trait expression is controlled
by a QTL. Segregation data from progeny test populations (e.g. F
3 or BCF
2) can be used in map construction. Marker-assisted selection can then be applied to
cross progeny based on marker-trait map associations (F
2, F
3), where linkage groups have not been completely disassociated by recombination events
(
i.
e., maximum disequilibrium).
[0093] Recombinant inbred lines (RIL) (genetically related lines; usually >F
5, developed from continuously selfing F
2 lines towards homozygosity) can be used as a mapping population. Information obtained
from dominant markers can be maximized by using RIL because all loci are homozygous
or nearly so. Under conditions of tight linkage (i.e., about <10% recombination),
dominant and co-dominant markers evaluated in RIL populations provide more information
per individual than either marker type in backcross populations (
Reiter et al., Proc. Natl. Acad. Sci. (U.S.A.) 89:1477-1481 (1992)). However, as the distance between markers becomes larger (
i.
e., loci become more independent), the information in RIL populations decreases dramatically
when compared to codominant markers.
[0094] Backcross populations (e.g., generated from a cross between a successful variety
(recurrent parent) and another variety (donor parent) carrying a trait not present
in the former) can be utilized as a mapping population. A series of backcrosses to
the recurrent parent can be made to recover most of its desirable traits. Thus a population
is created consisting of individuals nearly like the recurrent parent but each individual
carries varying amounts or mosaic of genomic regions from the donor parent. Backcross
populations can be useful for mapping dominant markers if all loci in the recurrent
parent are homozygous and the donor and recurrent parent have contrasting polymorphic
marker alleles (
Reiter et al., Proc. Natl. Acad. Sci. (U.S.A.) 89:1477-1481 (1992)). Information obtained from backcross populations using either codominant or dominant
markers is less than that obtained from F
2 populations because one, rather than two, recombinant gametes are sampled per plant.
Backcross populations, however, are more informative (at low marker saturation) when
compared to RILs as the distance between linked loci increases in RIL populations
(
i.
e. about .15% recombination). Increased recombination can be beneficial for resolution
of tight linkages, but may be undesirable in the construction of maps with low marker
saturation.
[0095] Near-isogenic lines (NIL) created by many backcrosses to produce an array of individuals
that are nearly identical in genetic composition except for the trait or genomic region
under interrogation can be used as a mapping population. In mapping with NILs, only
a portion of the polymorphic loci are expected to map to a selected region.
[0096] Bulk segregant analysis (BSA) is a method developed for the rapid identification
of linkage between markers and traits of interest (
Michelmore, et al., Proc. Natl. Acad. Sci. (U.S.A.) 88:9828-9832 (1991)). In BSA, two bulked DNA samples are drawn from a segregating population originating
from a single cross. These bulks contain individuals that are identical for a particular
trait (resistant or susceptible to particular disease) or genomic region but arbitrary
at unlinked regions (i.e. heterozygous). Regions unlinked to the target region will
not differ between the bulked samples of many individuals in BSA.
[0097] An alternative to traditional QTL mapping involves achieving higher resolution by
mapping haplotypes, versus individual markers (
Fan et al. 2006 Genetics). This approach tracks blocks of DNA known as haplotypes, as defined by polymorphic
markers, which are assumed to be identical by descent in the mapping population. This
assumption results in a larger effective sample size, offering greater resolution
of QTL. Methods for determining the statistical significance of a correlation between
a phenotype and a genotype, in this case a haplotype, may be determined by any statistical
test known in the art and with any accepted threshold of statistical significance
being required. The application of particular methods and thresholds of significance
are well with in the skill of the ordinary practitioner of the art.
[0098] The SNP markers of the present invention can be used to isolate or substantially
purify an allele of a QTL that is also located on linkage group associated with ASR
resistance locus 1, ASR resistance locus 2, ASR resistance locus 3, ASR resistance
locus 4, ASR resistance locus 5, ASR resistance locus 6, ASR resistance locus 7, ASR
resistance locus 8, ASR resistance locus 9, ASR resistance locus 10, ASR resistance
locus 11, ASR resistance locus 12, and ASR resistance locus 13. Construction of an
overlapping series of clones (a clone contig) across the region can provide the basis
for a physical map encompassing an allele of a fungal disease resistance QTL that
are located on a linkage group associated with ASR resistance locus 1, ASR resistance
locus 2, ASR resistance locus 3, ASR resistance locus 4, ASR resistance locus 5, ASR
resistance locus 6, ASR resistance locus 7, ASR resistance locus 8, ASR resistance
locus 9, ASR resistance locus 10, ASR resistance locus 11, ASR resistance locus 12,
and ASR resistance locus 13. The yeast artificial chromosome (YAC) cloning system
has facilitated chromosome walking and large-size cloning strategies. A sequence tag
site (STS) content approach utilizing the markers of the present invention can be
used for the construction of YAC clones across chromosome regions. Such an STS content
approach to the construction of YAC maps can provide a detailed and ordered STS-based
map of any chromosome region, including the region encompassing the allele of a QTL
is also located on a linkage group associated with ASR resistance locus 1, ASR resistance
locus 2, ASR resistance locus 3, ASR resistance locus 4, ASR resistance locus 5, ASR
resistance locus 6, ASR resistance locus 7, ASR resistance locus 8, ASR resistance
locus 9, ASR resistance locus 10, ASR resistance locus 11, ASR resistance locus 12,
and ASR resistance locus 13. YAC maps can be supplemented by detailed physical maps
are constructed across the region by using BAC, PAC, or bacteriophage P1 clones that
contain inserts ranging in size from 70 kb to several hundred kilobases (
Cregan, Theor. Appl.Gen. 78:919-928 (1999),
Sternberg, Proc. Natl. Acad. Sci. 87:103-107 (1990),
Sternberg, Trends Genet. 8:11-16 (1992);
Sternberg et al., New Biol. 2:151-162 (1990);
Ioannou et al., Nat. Genet. 6:84-89 (1994);
Shizuya et al., Proc. Natl. Acad. Sci. 89:8794-8797 (1992), all of which are herein incorporated by reference in their entirety).
[0099] Overlapping sets of clones are derived by using the available markers of the present
invention to screen BAC, PAC, bacteriophage P1, or cosmid libraries. In addition,
hybridization approaches can be used to convert the YAC maps into BAC, PAC, bacteriophage
P1, or cosmid contig maps. Entire YACs and products of inter-
Alu-PCR as well as primer sequences from appropriate STSs can be used to screen BAC,
PAC, bacteriophage P1, or cosmid libraries. The clones isolated for any region can
be assembled into contigs using STS content information and fingerprinting approaches
(
Sulston et al., Comput. Appl. Biosci. 4:125-132 (1988)).
[0100] The degeneracy of the genetic code, which allows different nucleic acid sequences
to code for the same protein or peptide, is known in the literature. As used herein
a nucleic acid molecule is degenerate of another nucleic acid molecule when the nucleic
acid molecules encode for the same amino acid sequences but comprise different nucleotide
sequences. An aspect of the present invention is that the nucleic acid molecules of
the present invention include nucleic acid molecules that are degenerate of the nucleic
acid molecule that encodes the protein(s) of the quantitative trait alleles.
[0101] Another aspect of the present invention is that the nucleic acid molecules of the
present invention include nucleic acid molecules that are homologues of the nucleic
acid molecule that encodes the one or more of the proteins associated with the QTL.
[0102] Exogenous genetic material may be transferred into a plant by the use of a DNA plant
transformation vector or construct designed for such a purpose. A particularly preferred
subgroup of exogenous material comprises a nucleic acid molecule of the present invention.
Design of such a vector is generally within the skill of the art (
See,
Plant Molecular Biology: A Laboratory Manual, eds. Clark, Springer, New York (1997), Examples of such plants, include, without limitation, alfalfa,
Arabidopsis, barley,
Brassica, broccoli, cabbage, citrus, cotton, garlic, oat, oilseed rape, onion, canola, flax,
maize, an ornamental plant, pea, peanut, pepper, potato, rice, rye, sorghum, soybean,
strawberry, sugarcane, sugarbeet, tomato, wheat, poplar, pine, fir, eucalyptus, apple,
lettuce, lentils, grape, banana, tea, turf grasses, sunflower, oil palm,
Phaseolus etc.
[0103] A construct or vector may include the endogenous promoter of the fungal disease resistance
QTL of the present invention. The characteristic of fungal disease resistance might
best be achieved by expressing the identified QTL protein with the endogenous promoter.
Alternatively, a heterologous promoter may be selected to express the protein or protein
fragment of choice. These promoters may be operably linked to a polynucleotide sequence
encoding the protein corresponding to the fungal resistance QTL. The heterologous
promoter may be one that is selected based upon maturation or flowering time, in that
timing of expression of the desired protein may be critical to the parameters affecting
the fungal disease resistance trait. Effective expression of the fungal disease resistance
QTL may require promoters that express in specific tissue types as well.
[0104] Alternatively, the promoters may be operably linked to other nucleic acid sequences,
such as those encoding transit peptides, selectable marker proteins, or antisense
sequences. The promoters may be selected on the basis of the cell type into which
the vector will be inserted or on the basis of its regulatory features. Examples of
such features include enhancement of transcriptional activity, inducibility, tissue-specificity,
and developmental stage-specificity. In plants, promoters that are inducible, of viral
or synthetic origin, constitutively active, temporally regulated, and spatially regulated
have been described (
Poszkowski, et al., EMBO J., 3: 2719, 1989;
Odell, et al., Nature, 313:810, 1985;
Chau et al., Science, 244:174-181. 1989). Often-used constitutive promoters include the CaMV 35S promoter (
Odell, et al., Nature, 313: 810, 1985), the enhanced CaMV 35S promoter, the Figwort Mosaic Virus (FMV) promoter (
Richins, et al., Nucleic Acids Res. 20: 8451, 1987), the nopaline synthase (nos) promoter (
Shaw et al., Nucleic Acids Res. 12: 7831-7846 (1984)) and the octopine synthase (ocs) promoter.
[0105] Useful inducible promoters include promoters induced by salicylic acid or polyacrylic
acids (PR-1;
Williams, et al., Biotechnology 10:540-543, 1992), induced by application of safeners (substituted benzenesulfonamide herbicides;
Hershey and Stoner, Plant Mol. Biol. 17: 679-690, 1991), heat-shock promoters (
Ou-Lee et al., Proc. Natl. Acad. Sci U.S.A. 83: 6815, 1986;
Ainley et al., Plant Mol. Biol. 14: 949, 1990), a nitrate-inducible promoter derived from the spinach nitrite reductase transcribable
polynucleotide sequence (
Back et al., Plant Mol. Biol. 17: 9, 1991), hormone-inducible promoters (
Yamaguchi-Shinozaki et al., Plant Mol. Biol. 15: 905, 1990), and light-inducible promoters associated with the small subunit of RuBP carboxylase
and LHCP families (
Kuhlemeier et al., Plant Cell 1: 471, 1989;
Feinbaum et al., Mol. Gen. Genet. 226: 449-456, 1991;
Weisshaar, et al., EMBO J. 10: 1777-1786, 1991;
Lam and Chua, J. Biol. Chem. 266: 17131-17135, 1990;
Castresana et al., EMBO J. 7: 1929-1936, 1988;
Schulze-Lefert, et al., EMBO J. 8: 651, 1989).
[0106] Particularly preferred promoters in the recombinant vector include the nopaline synthase
(NOS) promoter (Ebert et al., 1987), the octopine synthase (OCS) promoter (which is
carried on tumor-inducing plasmids of Agrobacterium tumefaciens), the caulimovirus
promoters such as the cauliflower mosaic virus (CaMV) 19S promoter (Lawton et al.,
1987), the CaMV 35S promoter (Odell et al., 1985), the figwort mosaic virus 35S-promoter
(Walker et al., 1987); the light-inducible promoter from the small subunit of ribulose-1,5-bisphosphate
carboxylase (ssRUBISCO); the EIF-4A promoter from tobacco (
Mandel, et al., Plant Mol. Biol, 29: 995-1004, 1995); the chitinase promoter from
Arabidopsis (
Samac, et al., Plant Cell, 3:1063-1072, 1991); the LTP (Lipid Transfer Protein) promoters from broccoli (
Pyee, et al., Plant J., 7: 49-59, 1995); petunia chalcone isomerase (
Van Tunen, et al., EMBO J. 7: 1257, 1988); bean glycine rich protein 1 (
Keller, et al., EMBO L., 8: 1309-1314, 1989); the Potato patatin (
Wenzler, et al., Plant Mol. Biol., 12: 41-50, 1989); the
Arabidopsis Actin 7 promoter (Genbank accession U27811.1 GI:1002528, 17-APR-1997 and
PCT application: WO0144457A2; the entirety of which is herein incorporated by reference); the
Arabidopsis Actin 8 promoter (
An et al., Plant J. 10: 107-121 (1996) and
PCT application: WO0144457A2); the
Arabidopsis Rubisco small subunit 4 promoter (
Krebbers et al., Plant Mol. Biol. 11: 745-759 (1988)); the
Brassica napin gene promoter (
U.S. Patent 5,420,034, the entirety of which is herein incorporated by reference); the
Arabidopsis Suc2 promoter (
Truernit et al., Planta 196: 564-570 (1995));
Arabidopsis elongation factor EF-1 alpha promoter (
Axelos et al., Mol. Gen. Genet. 219: 106-112 (1989)); and the
Glycine max 7sα beta conglycin promoter, Sphas (
Doyle et al., J. Biol. Chem. 261: 9228-9238 (1986)).
[0107] Constructs of the present invention may also include additional 5' untranslated regions
(5' UTR) or leaders of an mRNA polynucleotide molecule or gene which can play an important
role in translation initiation. Some 5' UTRs may act as translational enhancers and
may also be incorporated as part of the recombinant vector. For example, non-translated
5' leader polynucleotide molecules derived from heat shock protein genes have been
demonstrated to enhance gene expression in plants (see for example,
U.S. Patent 5,659,122, the entirety of which is herein incorporated by reference and
U.S. Patent 5,362,865, the entirety of which is herein incorporated by reference). Thus the recombinant
vector may preferably contain one or more 5' non-translated leader sequences which
serve to enhance expression of the nucleic acid sequence. Such enhancer sequences
may be desirable to increase or alter the translational efficiency of the resultant
mRNA. Preferred 5' nucleic acid sequences include the
Arabidopsis Actin 7 leader (Genbank accession U27811.1 GI:1002528, 17-APR-1997 and
PCT application: WO0144457A2; the entirety of which is herein incorporated by reference); the
Arabidopsis Actin 8 leader (
An et al., Plant J. 10: 107-121 (1996) and
PCT application: WO0144457A2); the
Arabidopsis Rubisco small subunit 4 leader (
Krebbers et al., Plant Mol. Biol. 11: 745-759 (1988)); the
Brassica napin gene leader (
U.S. Patent 5,420,034, the entirety of which is herein incorporated by reference); the
Arabidopsis Suc2 leader (
Truernit et al., Planta 196: 564-570 (1995)); the
Petunia hybrida Hsp70 gene leader (
Winter et al., Mol. Gen. Genet. 211: 315-319 (1988)): the
Arabidopsis EPSPS gene leader (
Klee et al., Mol. Gen. Genet. 210: 437-442 (1987)); the
Arabidopsis elongation factor EF-1 alpha leader (
Axelos et al., Mol. Gen. Genet. 219: 106-112 (1989)); and the
Glycine max 7sα beta conglycin leader (
Doyle et al., J. Biol. Chem. 261: 9228-9238 (1986)). These additional upstream regulatory polynucleotide molecules may be derived from
a source that is native or heterologous with respect to the other elements present
on the construct.
[0108] In addition, constructs may include additional regulatory polynucleotide molecules
from the 3'-untranslated region (3' UTR) of plant genes. A 3' UTR or terminator typically
provides a transcriptional termination signal, and a polyadenylation signal which
functions in plants to cause the addition of adenylate nucleotides to the 3' end of
the mRNA. Usually, nucleic acid sequences located a few hundred base pairs downstream
of the polyadenylation site serve to terminate transcription. In addition, some 3'
UTRs provide additional properties such as enhancing the stability of the mRNA as
in the potato proteinase inhibitor II gene 3' UTR (
An et al., The Plant Cell 1: 115-122 (1989)). Other 3' UTRs may provide sequences that enhance degredation of the mRNA such
as the 5'-UUAUUUAUU-3' motif shown to contribute to lower stability of RNA messages
in animal cells (
Zubiaga et al., Mol. Cell Biol. 15: 2219-2230 (1995)). These additional downstream regulatory polynucleotide molecules may be derived
from a source that is native or heterologous with respect to the other elements present
on the construct.
[0109] Preferred 3' UTRs or terminators are the potato proteinase inhibitor II gene 3' UTR
(
An et al., The Plant Cell 1: 115-122 (1989)); the pea Rubisco small subunit E9 terminator (
Coruzzi et al., EMBO J. 3: 1671-1679 (1984)); the cauliflower mosaic virus 35S terminator; the
Brassica napin gene terminator (
U.S. Patent 5,420,034); the
Glycine max 7sα beta conglycin gene terminator (
Doyle et al., J. Biol. Chem. 261: 9228-9238 (1986)); the Phaseoulus vulgaris Arc5 terminator (
Goossens et al., Eur. J. Biochem. 225: 787-795 (1994)); the
Agrobacterium tumefaciens nopaline synthase terminator (Rojiyaa
et al., 1987, Genbank Accession E01312 and U.S. Patent Application
US20020192813A1, the entirety of which is herein incorporated by reference); and the
Glycine max ADR12 gene terminator (
Datta et al., Plant Mol. Biol. 21: 859-869 (1993)).
[0111] A vector or construct may also include a selectable marker. Selectable markers may
also be used to select for plants or plant cells that contain the exogenous genetic
material. Examples of such include, but are not limited to, a neo gene (
Potrykus et al., Mol. Gen. Genet. 199:183-188 (1985)), which codes for kanamycin resistance and can be selected for using kanamycin,
G418, etc.; a bar gene which codes for bialaphos resistance; a mutant EPSP synthase
gene (
Hinchee et al., Bio/Technology 6:915-922 (1988)), which encodes glyphosate resistance; a nitrilase gene which confers resistance
to bromoxynil (
Stalker et al., J. Biol. Chem. 263:6310-6314 (1988)); a mutant acetolactate synthase gene (ALS) which confers imidazolinone or sulphonylurea
resistance (for example,
U.S. Patent 6,222,100, the entirety of which is herein incorporated by reference); a methotrexate resistant
DHFR gene (
Thillet et al., J. Biol. Chem. 263:12500-12508 (1988)); Dicamba tolerance conferred, for example, by a gene for dicamba monooxygenase
(DMO) from Pseudomonas maltophilia (
US Patent Application 20030135879, the entirety of which is herein incorporated by reference).
[0112] A vector or construct may also include a screenable marker. Screenable markers may
be used to monitor expression. Exemplary screenable markers include a β-glucuronidase
or uidA gene (GUS) which encodes an enzyme for which various chromogenic substrates
are known (
Jefferson, Plant Mol. Biol, Rep. 5:387-405 (1987), the entirety of which is herein incorporated by reference;
Jefferson et al., EMBO J. 6:3901-3907 (1987), the entirety of which is herein incorporated by reference); an R-locus gene, which
encodes a product that regulates the production of anthocyanin pigments (red color)
in plant tissues (
Dellaporta et al., Stadler Symposium 11:263-282 (1988), the entirety of which is herein incorporated by reference); a β-lactamase gene
(
Sutcliffe et al., Proc. Natl. Acad. Sci. (U.S.A.) 75:3737-3741 (1978), the entirety of which is herein incorporated by reference), a gene which encodes
an enzyme for which various chromogenic substrates are known (
e.
g., PADAC, a chromogenic cephalosporin); a luciferase gene (
Ow et al., Science 234:856-859 (1986), the entirety of which is herein incorporated by reference); a xylE gene (
Zukowsky et al., Proc. Natl. Acad. Sci. (U.S.A.) 80:1101-1105 (1983), the entirety of which is herein incorporated by reference) which encodes a catechol
dioxygenase that can convert chromogenic catechols; an α-amylase gene (
Ikatu et al., Bio/Technol. 8:241-242 (1990), the entirety of which is herein incorporated by reference); a tyrosinase gene (
Katz et al., J. Gen. Microbiol. 129:2703-2714 (1983), the entirety of which is herein incorporated by reference) which encodes an enzyme
capable of oxidizing tyrosine to DOPA and dopaquinone which in turn condenses to melanin;
and an α-galactosidase.
[0113] Any of the techniques known in the art for introduction of transgenes into plants
may be used to prepare a plant resistant to fungal disease in accordance with the
invention. Suitable methods for transformation of plants are believed to include virtually
any method by which DNA can be introduced into a cell, such as by electroporation
as illustrated in
U.S. Patent No. 5,384,253; microprojectile bombardment as illustrated in
U.S. Patent Nos. 5,015,580;
5,550,318;
5,538,880;
6,160,208;
6,399,861; and
6,403,865; Agrobacterium-mediated transformation as illustrated in
U.S. Patent Nos. 5,635,055;
5,824,877;
5,591,616;
5,981,840; and
6,384,301; and protoplast transformation as illustrated in
U.S. Patent No. 5,508,184. Through the application of techniques such as these, the cells of virtually any
plant species may be stably transformed, and these cells developed into transgenic
plants. Techniques useful in the context of cotton transformation are disclosed in
U.S. Patent Nos. 5,846.797,
5,159,135,
5,004,863, and
6,624,344; and techniques for transforming Brassica plants in particular are disclosed, for
example, in
U.S. Patent 5,750,871; and techniques for transforming soybean are disclosed in for example in
Zhang et al. (Plant Cell Tissue Organ Cult 56:37-46 (1999) and
US Patent 6,384,301.
[0114] Having now generally described the invention, the same will be more readily understood
through reference to the following examples which are provided by way of illustration,
and are not intended to be limiting of the present invention, unless specified.
Examples
Example 1: Breeding of Near-Isogenic Lines containing ASR resistance loci
[0115] One thousand, four hundred single nucleotide polymorphism (SNP) markers, randomly
distributed across the 20 linkage groups of the soybean genetic linkage map, were
used to identify SNP markers tightly linked to the ASR resistance locus 1 locus. A
panel of soybean lines consisting of near-isogenic lines (NILs) developed from a cross
between Williams 82 and ASR resistance locus 1 donor, PI 200492. Derivative lines
of PI 200492 were used to identify SNP markers that were polymorphic between Williams
82 and PI 200492. These polymorphic SNP markers were then used to identify the map
location of ASR resistance locus 1 using a segregating backcross population, L85-2378.
L85-2378 was developed by crossing Williams 82 with PI 200492 and five backcross cycles,
or essentially 6 doses of Williams 82, were made to recover most of Williams 82's
desirable traits. Thus L85-2378 is created consisting of individuals nearly like the
recurrent parent, Williams 82, but each individual NIL carries varying amounts or
mosaic of genomic regions from the donor parent, PI 200492.
[0116] The entire population was genotyped with the polymorphic SNP markers identified above
and was subsequently evaluated for soybean rust resistance using a greenhouse assay.
Associations between SNP marker genotype and soybean rust resistance phenotype were
evaluated. SNP markers found to be in high linkage disequilibria with ASR resistance
locus 1 disease phenotypic response were NS0093250, NS0119710, NS0103004, NS0099454,
NS0102630, NS0102915, NS0102913, NS0123728, NS0129943, NS0102168, NS0092723, NS0098177,
NS0127343, and NS0101121, and are presented in Table 1 and indicated as SEQ ID NOs:
67 through 80. All of these SNP markers map to a region on linkage group G of the
public soybean genetic linkage map. Table 1 lists sequences for PCR amplification
primers, indicated as SEQ ID NOs: 1 through 28, and probes, indicated as SEQ ID NOs:
100 through 127, corresponding to these SNP markers. Two SNP markers were identified
as being useful in monitoring the positive introgression of ASR resistance locus 1
and correspond to SNP markers NSO1029 and NSO129943 and correspond to SEQ ID NO: 73
and SEQ ID NO: 75, respectively.
[0117] The efficacy of ASR resistance locus 1 against soybean rust isolates from Alabama
was also evaluated in the following F2:3 populations: AG4403 x PI 200492, AG3302 x
PI 200492, AG3201 x PI 200492, AG26932 x PI 200492, AG2402 x PI 200492. In each of
the populations, a 3:1 segregation ratio was observed indicating a single dominant
gene inheritance pattern.
[0118] Following the procedure described for ASR resistance locus 1, the ASR resistance
locus 3 locus was mapped using NILs developed from the cross between Williams 82 and
the donor parent, PI 462312, followed by five backcross cycles, or essentially 6 doses
of Williams 82, were made to recover most of Williams 82's desirable traits. Thus
L85-2378 is created consisting of individuals nearly like the recurrent parent, Williams
82 but each individual near isogenic line carries varying amounts or mosaic of genomic
regions from the donor parent, PI 200492. The entire population was genotyped with
the set of polymorphic SNP markers identified above and was subsequently evaluated
for soybean rust resistance using a greenhouse assay. Associations between SNP marker
genotype and soybean rust resistance phenotype were evaluated. SNP markers found to
be in high linkage disequilibria with ASR resistance locus 3 were NS0099746, NS0123747,
NS0126598, NS0128378, NS0096829, NS0125408, NS0098902, NS0099529, NS0097798, NS0137477,
NS0095322, NS0136101, and NS0098992, and are presented in Table 1 and indicated as
SEQ ID NOs: 81 through 93. These markers were all mapping to LG C2 of the public soybean
genetic map. Table 1 lists sequences for PCR amplification primers, indicated as SEQ
ID NOs: 29 through 54, and probes, indicated as SEQ ID NOs: 128 through 153, corresponding
to these SNP markers. The marker used to monitor the introgression of ASR resistance
locus 3 corresponds to SNP marker NSO13747 and is indicated as SEQ ID NO: 90. To confirm
the putative location of ASR resistance locus 3, a segregating F3:4 population was
developed between AVRDC-8 and AG4403. AVRDC-8 is line developed by Asian Vegetable
Research and Development Center in Taiwan by crossing Ankur (ASR resistance locus
3 containing line) and PI 230970 (ASR resistance locus 2 donor). This population is
currently being genotyped for SNP markers and evaluated for resistance reaction against
a soybean rust isolate from Loxley, AL to validate the location of ASR resistance
locus 3.
[0119] The approximate locations of ASR resistance locus 2 and ASR resistance locus 4 were
later determined based upon a survey of polymorphisms between a panel of PI lines
that are known to contain either ASR resistance locus 2 or ASR resistance locus 4,
PI 230970, PI 459025B, the donor of ASR resistance locus 2 and ASR resistance locus
4, respectively, and other lines that were reported in literature to contain either
QTL. Based on the polymorphism survey, any polymorphic SNP marker is a candidate region
near the ASR resistance loci. For ASR resistance locus 2, two candidate regions were
identified and the locus is most likely located on linkage group J, near or within
the disease resistance cluster Brown Stem Rot, Soybean Cyst Nematode resistance and
Frog Eye Leaf Spot, or within linkage group N. The ASR resistance locus 4 is likely
located on linkage group N.
Table 1. SNP markers for identification and selection of ASR resistance locus 1 and
ASR resistance locus 3.
MARKER |
SEQ ID |
SEQ ID FORWARD PRIMER |
SEQ ID REVERSE PRIMER |
SEQ ID PROBE 1 |
SEQ ID PROBE 2 |
NS0093250 |
67 |
1 |
2 |
100 |
101 |
NS0119710 |
68 |
3 |
4 |
102 |
103 |
NS0103004 |
69 |
5 |
6 |
104 |
105 |
NS0099454 |
70 |
7 |
8 |
106 |
107 |
NS0102630 |
71 |
9 |
10 |
108 |
109 |
NS0102915 |
72 |
11 |
12 |
110 |
111 |
NS0102913 |
73 |
13 |
14 |
112 |
113 |
NS0123728 |
74 |
15 |
16 |
114 |
115 |
NS0129943 |
75 |
17 |
18 |
116 |
117 |
NS0102168 |
76 |
19 |
20 |
118 |
119 |
NS0092723 |
77 |
21 |
22 |
120 |
121 |
NS0098177 |
78 |
23 |
24 |
122 |
123 |
NS0127343 |
79 |
25 |
26 |
124 |
125 |
NS0101121 |
80 |
27 |
28 |
126 |
127 |
NS0099746 |
81 |
29 |
30 |
128 |
129 |
NS0123747 |
82 |
31 |
32 |
130 |
131 |
NS0126598 |
83 |
33 |
34 |
132 |
133 |
NS0128378 |
84 |
35 |
36 |
134 |
135 |
NS0096829 |
85 |
37 |
38 |
136 |
137 |
NS0125408 |
86 |
39 |
40 |
138 |
139 |
NS0098902 |
87 |
41 |
42 |
140 |
141 |
NS0099529 |
88 |
43 |
44 |
142 |
143 |
NS0097798 |
89 |
45 |
46 |
144 |
145 |
NS0137477 |
90 |
47 |
48 |
146 |
147 |
NS0095322 |
91 |
49 |
50 |
148 |
149 |
NS0136101 |
92 |
51 |
52 |
150 |
151 |
NS0098982 |
93 |
53 |
54 |
152 |
153 |
Example 2: Collection and propagation of spores.
[0120] Asian Soybean Rust urediniospores from
Phakopsora pachyrhizi were collected from infected plants at the Monsanto Loxley Agronomy station (Loxley,
AL), herein referred to as the Loxley strain.
[0121] Soybean plants were inoculated by spraying the underside of the leaves with spores
suspended in water containing 0.01% Tween-20. Lesion development was visible without
magnification at around 7 to 10 days with sporulation occurring at 12 to 14 days after
infection. Spores from the infected plants were collected and resuspended in sterile
deionized water containing 0.01% Tween 20. The spore concentration was determined
using a hemacytometer.
Example 3: Detached leaf assay for Asian Soybean Rust Resistance
[0122] Two types of leaf tissue were assessed for ASR disease phenotyping. Unifoliates leaves,
seven to ten days after emergence, or V3 trifoliate leaves, twenty-one to twenty-eight
after emergence, were assessed. At about two days after emergence from the soil, the
soybean plant bears a pair of unifoliate leaves which are fully unfurled about five
days later and constitute the first 'true leaves'. At about seven days after emergence,
the trifoliate leaves appear (comprising three leaves at the end of one petiole).
Three sets emerge in sequence and the first trifoliate leaves are denoted as the V1
stage, and are fully expanded at ten days after emergence. The next two V stages occur
a week apart. Notably, the leaves are inoculated for disease after they have both
unfurled and hardened, i.e. not new and green. The unifoliates tend to harden very
quickly, around 8-10d after emergence, while V2 and V3 trifoliates may not even unfurl
completely until up to 24-28 days after emergence.
[0123] Three 3.2 cm diameter Watmann #1 filter papers are placed in each of 6 wells of a
6-well tissue culture plate (well volume is 15.5 milliliters). The leaves are cut
into 3 centimeter by 3 centimeter pieces and placed on top of the Watmann filter papers
with the bottom (stomatal side) of the leaf facing upwards. Approximately 2.0 milliliters
of sterile deionized water is put into each well of the 6-well tissue culture plate.
Asian Soybean Rust urediniospores from
Phakopsora pachyrhizi are suspended in sterile deionized water containing 0.01% tween 20 at a concentration
of 1 X 10
5 urediniospores per milliliter. Approximately 50 microliters of spore suspension is
applied to each leaf piece using an airbrush (Model Badger 155 Anthem, Badger AirBrush
Co., Franklin Park, IL) with a compressor (Model TC-20, Airbrush Depot, San Diego,
CA) setting of 1 kilogram per square centimeter to wetness. The 6-well plate is then
sealed with parafilm and placed in a growth chamber set to 22 degrees Celsius, with
a photoperiod of 12 hours daylength. The plates are checked every 2 or 3 days to monitor
the progression of disease and to assure the wells have not dried out. Deionized water
is added to make up the original volume in the well when needed or incubator relative
humidity is adjusted to approximately 80%. Early symptoms of developing lesions should
be evident under a dissecting microscope about 3 to 5 days after inoculation. Sporulating
lesions should be evident 9 to 14 days after inoculation. Average soybean rust severity
scores are calculated from multiple trials. The rust severity score uses a rating
scale from 1 to 5; 1 - being immune, 2 - demonstrating red/brown lesions over less
than 50% of the leaf area, 3 - demonstrating red/brown lesions over greater than 50%
of the leaf area, 4 - demonstrating tan lesions over less than 50% of the leaf area
and 5 - demonstrating tan lesions over greater than 50% of the leaf area. Leaf sections
can remain viable in this assay for up to 2 months.
[0124] Experiments using Asian Soybean Rust susceptible soybean, Lee 74 demonstrate consistently
high levels of infection for each assay performed. Further experiments evaluating
putative resistant germplasm were able to differentiate tolerant from susceptible
accessions as demonstrated in Table 2. Accession PI 200487 demonstrated a slow rust
resistance phenotype. Efforts are underway to identify markers that will be used in
the introgression of the resistance locus identified in PI 200487 into elite germplasm.
[0125] In addition, comparison of ASR evaluation of unifoliate and trifoliate leaf tissue
showed it takes approximately 45 days from seed to data point for trifoliates and
approximately 23 days for unifoliates. By cutting the assay time in half, this significantly
economizes the detached leaf assay and time required to determine disease resistance
rating. By saving 3 weeks, plants can be propagated on a faster time scale and susceptible
plants can be culled sooner, saving field and greenhouse space.
Table 2. Average rust score for resistant and susceptible accessions as determined
using unifoliate and trifoliate leaf tissue; "-" indicates the assay was not performed.
Accession |
Average Rust Severity Score Detached Unifoliate |
Average Rust Severity Score Detached Leaf |
Lee 74 |
5.0 |
5 |
PI 200487 |
1.89 |
2.25 |
PI 200492 (ASR resistance locus 1) |
1.00 |
2 |
PI 200499 |
- |
5 |
PI 230970 |
2.5 |
3 |
PI 368038 |
- |
3 |
PI 368039 |
- |
2 |
PI 462312 |
- |
2 |
PI 547875 |
- |
2 |
PI 547878 |
- |
4.25 |
PI 547879 |
- |
5 |
Tiana |
- |
5 |
Williams |
- |
5 |
AVRDC-8 |
1.8 |
2.25 |
Dowling |
- |
5 |
Example 4: Testing of Elite crosses for resistance to P. pachyrizi with introgressed ASR resistance locus 1, ASR resistance locus 2 and ASR resistance
locus 3.
[0126] Crosses with donor resistant parent line, PI 200492, containing ASR resistance locus
1 were performed with various elite lines of soybean to monitor the positive introgression
of ASR resistance locus 1. Leaf assays for resistance to the Loxley strain were performed
using lines derived from crosses with the resistant parent line accession, PI 200492
(ASR resistance locus 1) as well as known resistant accessions (PI 230970 (ASR resistance
locus 2) and PI 462312 (ASR resistance locus 3)) and susceptible elite lines. The
resistance scores for all lines tested are presented in Table 3. Average rust severity
scores were derived from 4 plants, each with 4 replications and rated on 4 different
days (10DAI, 17DAI, 24DAI, 32DAI).
Table 3. Average Rust Severity Score of ASR backcross events and elite lines.
Cross |
Progeny From Cross |
ASR resistance locus Loci |
Average Rust Severity Score |
Multiple crosses to introgress both ASR resistance locus 2 and ASR resistance locus
3 |
AVRDC-8 |
ASR resistance locus 2/ASR resistance locus 3 |
1.7 |
Known Susceptible Line |
Dowling |
Susceptible |
5 |
GL_AG4801//L85-2378/L86-1752 |
JN1137.1 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4801//L85-2378/L86-1753 |
JN1137.2 |
ASR resistance locus 1 (MAS) |
5 |
GL_AG4801//L85-2378/L86-1754 |
JN1137.3 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4801//L85-2378/L86-1755 |
JN1137.4 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4801//L85-2378/L86-1752 |
JN1153.1 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4801//L85-2378/L86-1753 |
JN1153.2 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4801//L85-2378/L86-1754 |
JN1153.3 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4801//L85-2378/L86-1755 |
JN1153.4 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4801//L85-2378/L86-1752 |
JN1160.1 |
ASR resistance locus 1 (MAS) |
4.8 |
GL_AG4801//L85-2378/L86-1752 |
JN1160.2 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4801//L85-2378/L86-1752 |
JN1160.3 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4801//L85-2378/L86-1752 |
JN1160.4 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4801//L85-2378/L86-1752 |
JN1163.1 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4801//L85-2378/L86-1752 |
JN1163.2 |
ASR resistance locus 1 (MAS) |
4.8 |
GL_AG4801//L85-2378/L86-1752 |
JN1163.3 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4801//L85-2378/L86-1752 |
JN1163.4 |
ASR resistance locus 1 (MAS) |
5 |
GL_AG5501//L85-2378/L86-1752 |
JN1691.1 |
ASR resistance locus 1 (MAS) |
4.5 |
GL_AG5501//L85-2378/L86-1752 |
JN1691.2 |
ASR resistance locus 1 (MAS) |
4.6 |
GL_AG5501//L85-2378/L86-1752 |
JN1691.3 |
ASR resistance locus 1 (MAS) |
4.6 |
GL_AG5501//L85-2378/L86-1752 |
JN1691.4 |
ASR resistance locus 1 (MAS) |
3 |
GL_AG5501//L85-2378/L86-1752 |
JN1692.1 |
ASR resistance locus 1 (MAS) |
1.1 |
GL_AG5501//L85-2378/L86-1752 |
JN1692.2 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG5501//L85-2378/L86-1752 |
JN1692.3 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG5501//L85-2378/L86-1752 |
JN1692.4 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG5501//L85-2378/L86-1752 |
JN1742.1 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG5501//L85-2378/L86-1752 |
JN1742.2 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG5501//L85-2378/L86-1752 |
JN1742.3 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG5501//L85-2378/L86-1752 |
JN1742.4 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG5501//L85-2378/L86-1752 |
JN1765.1 |
ASR resistance locus 1 (MAS) |
1.2 |
GL_AG5501//L85-2378/L86-1752 |
JN1765.2 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG5501//L85-2378/L86-1752 |
JN1765.3 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG5501//L85-2378/L86-1752 |
JN1765.4 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG5501//L85-2378/L86-1752 |
JN1774.1 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG5501//L85-2378/L86-1752 |
JN1774.2 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG5501//L85-2378/L86-1752 |
JN1774.3 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG5501//L85-2378/L86-1752 |
JN1774.4 |
ASR resistance locus 1 (MAS) |
1 |
GL_CGL4504D0C//L85-2378/L86-1752 |
JN1866.1 |
ASR resistance locus 1 (MAS) |
1 |
GL_CGL4504D0C//L85-2378/L86-1752 |
JN1866.2 |
ASR resistance locus 1 (MAS) |
1 |
GL_CGL4504D0C//L85-2378/L86-1752 |
JN1866.3 |
ASR resistance locus 1 (MAS) |
1 |
GL_CGL4504D0C//L85-2378/L86-1752 |
JN1866.4 |
ASR resistance locus 1 (MAS) |
1 |
GL_CGL5400E1X//L85-2378/L86-1752 |
JN2242.1 |
ASR resistance locus 1 (MAS) |
1 |
GL_CGL5400E1X//L85-2378/L86-1752 |
JN2242.2 |
ASR resistance locus 1 (MAS) |
1 |
GL_CGL5400E1X//L85-2378/L86-1752 |
JN2242.3 |
ASR resistance locus 1 (MAS) |
1 |
GL_CGL5400E1X//L85-2378/L86-1752 |
JN2242.4 |
ASR resistance locus 1 (MAS) |
1 |
GL_CGL5400E1X//L85-2378/L86-1752 |
JN2243.1 |
ASR resistance locus 1 (MAS) |
1 |
GL_CGL5400E1X//L85-2378/L86-1752 |
JN2243.2 |
ASR resistance locus 1 (MAS) |
2.4 |
GL_CGL5400E1X//L85-2378/L86-1752 |
JN2243.3 |
ASR resistance locus 1 (MAS) |
1 |
GL_CGL5400E1X//L85-2378/L86-1752 |
JN2243.4 |
ASR resistance locus 1 (MAS) |
1.3 |
GL_CGL5400E1X//L85-2378/L86-1752 |
JN2250.1 |
ASR resistance locus 1 (MAS) |
1 |
GL_CGL5400E1X//L85-2378/L86-1752 |
JN2250.2 |
ASR resistance locus 1 (MAS) |
1 |
GL_CGL5400E1X//L85-2378/L86-1752 |
JN2250.3 |
ASR resistance locus 1 (MAS) |
1.2 |
GL_CGL5400E1X//L85-2378/L86-1752 |
JN2250.4 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4403//L85-2378/L86-1752 |
JN774.1 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4403//L85-2378/L86-1752 |
JN774.2 |
ASR resistance locus 1 (MAS) |
1.1 |
GL_AG4403//L85-2378/L86-1752 |
JN774.3 |
ASR resistance locus 1 (MAS) |
1 |
GL_AG4403//L85-2378/L86-1752 |
JN774.4 |
ASR resistance locus 1 (MAS) |
1 |
[0127] Lines containing the ASR resistance locus 1 locus showed greatest resistance to the
Loxley strain. Introgression of the ASR resistance locus 1 was confirmed by MAS.
Example 5: Testing of Soybean Accessions for ASR Resistance using the Detached Leaf
Assay
[0128] Seven hundred putative ASR resistant accessions were identified based upon greenhouse
assays, using a mixed population of ASR isolates of foreign origin. Leaf assays for
resistance to ASR were performed as described in Example 3 using a subset of two hundred
and fifty of the seven hundred USDA putative resistant accessions. A complementary
set of two hundred and fifty ASR susceptible accessions from the USDA were selected
for comparison in the leaf assay based upon matching maturities and geographic origins
to the two hundred and fifty resistant accessions. The average rust severity scores
of the most resistant accessions (those exhibiting an average rust severity score
from 1 to 2) is presented in Table 4 below. One thousand, four hundred SNP markers,
distributed every 5 centimorgans across the 20 linkage groups of the soybean genetic
linkage map, will be used to identify markers useful in following the introgression
of the ASR resistance loci possessed by the resistant accessions into elite germplasm.
Table 4. Average Rust Severity Score ASR Resistant Accessions.
Accession |
Average Rust Severity Score |
PI200488 |
1.0 |
PI200492 |
1.0 |
PI203398 |
1.0 |
PI307884B |
1.0 |
PI416764 |
1.0 |
PI416826A |
1.0 |
PI417117 |
1.0 |
PI417132 |
1.0 |
PI423967 |
1.0 |
PI506947 |
1.0 |
PI507009 |
1.0 |
PI507259 |
1.0 |
PI561305 |
1.0 |
PI567031B |
1.0 |
PI567034 |
1.0 |
PI567056A |
1.0 |
PI567058D |
1.0 |
PI567190 |
1.0 |
PI605773 |
1.0 |
PI605829 |
1.0 |
PI605865B |
1.0 |
PI379620 |
1.3 |
PI416873B |
1.3 |
PI417128 |
1.3 |
PI417463 |
1.3 |
PI567123A |
1.3 |
PI578457A |
1.3 |
PI615437 |
1.3 |
PI379621 |
1.3 |
PI567102B |
1.3 |
PI594172A |
1.3 |
PI628932 |
1.3 |
PI079648 |
1.5 |
PI291309C |
1.5 |
PI416886 |
1.5 |
PI417503 |
1.5 |
PI506491 |
1.5 |
PI506677 |
1.5 |
PI506695 |
1.5 |
PI507193 |
1.5 |
PI567046A |
1.5 |
PI567053 |
1.5 |
PI567189A |
1.5 |
PI605891B |
1.5 |
PI200455 |
1.8 |
PI232989 |
1.8 |
PI594494A |
1.8 |
PI597405D |
1.8 |
PI069533 |
2.0 |
PI084674 |
2.0 |
PI230970 |
2.0 |
PI291278 |
2.0 |
PI341252 |
2.0 |
PI417126 |
2.0 |
PI417134 |
2.0 |
PI417208 |
2.0 |
PI423923 |
2.0 |
PI437609A |
2.0 |
PI471900 |
2.0 |
PI497969 |
2.0 |
PI506628 |
2.0 |
PI547875 |
2.0 |
PI567024 |
2.0 |
PI567025A |
2.0 |
PI578471A |
2.0 |
PI594512C |
2.0 |
PI594561 |
2.0 |
PI605781A |
2.0 |
PI605838 |
2.0 |
PI606405 |
2.0 |
PI606440A |
2.0 |
PI615445 |
2.0 |
[0129] In addition, SNP markers distributed proximal and distal to ASR resistance locus
3 were genotyped for a set of eighty-nine resistant accessions. Four additional SNP
markers (NS0103749, NS0118897, NS0119715, and NS0130920) were found to be associated
with ASR resistnce locus 3 and are listed in Table and indicated as SEQ ID NOs: 94
through 97. Table 5 lists sequences for PCR amplification primers, indicated as SEQ
ID NOs: 55 through 62, and probes, indicated as SEQ ID NOs: 154 through 161, corresponding
to these SNP markers.
[0130] This information will be used to identify novel resistance sources useful in prioritizing
the introgression of the ASR and other pathogen resistance loci.
Table 5. SNP markers for identification and selection of ASR resistance locus 3.
MARKER |
SEQ ID |
SEQ ID FORWARD PRIMER |
SEQ ID REVERSE PRIMER |
SEQ ID PROBE 1 |
SEQ ID PROBE 2 |
NS0103749 |
94 |
55 |
56 |
154 |
155 |
NS0118897 |
95 |
57 |
58 |
156 |
157 |
NS0119715 |
96 |
59 |
60 |
158 |
159 |
NS0130920 |
97 |
61 |
62 |
160 |
161 |
Example 6. Using association studies to identify QTL that confer fungal disease resistance
[0131] To identify regions or genes associated with the disease is the first step toward
developing resistant varieties. Four loci for rust resistance (ASR resistance locus
1, ASR resistance locus 2, ASR resistance locus 3, ASR resistance locus 4) were previously
identified. In this example, linkage disequilibrium and haplotype association mapping
were applied to a case-control data sample from soybean germplasm.
[0132] Four hundred ninety-two soybean lines (246 resistant-susceptible pairs) were scored
for rust resistance as well as fingerprinted using 797 SNPs. Disease resistance was
scored in 1 to 5 scales to a mixture of
Phakopsora pachyrhizi isolates, with less than 3 as resistant and greater than 4 as susceptible. Specifically,
case-control testing, Fishers' exact test, single marker F-test, and haplotype trend
regression were explored on window sizes of 3, 5 and 9 consecutive SNPs. Multiple
testing results significantly associate two SNP markers from two separate haplotype
windows, referred to herein as in fungal disease resistance haplotype windows 1 and
2, on chromosome 13 24-45 cM) with resistance to fungal disease. The SNP markers NS0103033
and NS0124935 are located in fungal disease resistance haplotype windows 1 and 2 respectively.
The primers for NS0103033 (SEQ ID NO: 98) are indicated in SEQ ID NOs: 63 and 64 and
the probes are indicated in SEQ ID NOs: 162 and 163. The primers for NS0124935 (SEQ
ID NO: 99) are indicated in SEQ ID NOs: 65 and 66 and the probes are indicated in
SEQ ID NOs: 164 and 165. Resistance scores for each of the haplotypes and the marker
allele for each haplotype are indicated in Table 5. Each window is designated by five
SNP markers and the alleles for each is indicated as haplotype sequence. The allele
for NS0103033 in haplotype window 1 and NS0124935 in haplotype window 2 are indicated
in bold. For NS0103033, the SNP is actually a 9-bp indel where "Z" represents the
deletion (*********) and "W" represents the insertion (GAAGTGGAT).
[0133] Varieties containing resistant haplotypes from haplotype window 1 and/or 2 are indicated
in table 6. This mapping effort has identified additional ASR disease resistance QTLs
in addition to the previously defined ASR resistance loci.
Table 5. Summary scoring for lines containing resistant haplotypes in ASR resistance
haplotype windows 1 and 2. A resistance score of 0 indicates the line was resistant
and a score of 1 indicates the line was designated susceptibe.
ASR resistance locus |
Haplotype Window 1 |
Haplotype sequence |
Resistance Score |
|
|
|
0 |
1 |
5 |
Haplotype 1 |
AAZA? |
5 |
0 |
6 |
Haplotype 2 |
AGWGA |
26 |
10 |
7 |
Haplotype 3 |
AGWGG |
34 |
15 |
8 |
Haplotype 4 |
TAZAG |
5 |
0 |
9 |
Haplotype 5 |
TAZGA |
13 |
5 |
ASR resistance locus |
Haplotype Window 1 |
Haplotype sequence |
Resistance Score |
|
|
|
0 |
1 |
10 |
Haplotype 6 |
CGTTG |
8 |
1 |
11 |
Haplotype 7 |
GGTTC |
26 |
11 |
12 |
Haplotype 8 |
GGCCC |
12 |
6 |
13 |
Haplotype9 |
GGT-C |
4 |
0 |
Table 6. Disease ratings for resistant germplasm containing haplotypes in ASR resistance
windows 1 and/or 2 on chromosome 13.
Line |
Rating |
Resistance haplotype from haplotype window 1 |
Resistance haplotype from haplotype window 2 |
PI164885 |
2.5 |
X |
X |
PI165524 |
2 |
X |
X |
PI166028 |
2 |
|
X |
PI189968 |
2 |
X |
X |
PI200446 |
2 |
X |
|
PI200488 |
2.5 |
|
X |
PI205901B |
2.5 |
X |
|
PI222549 |
2.5 |
X |
|
PI224270 |
2.5 |
X |
|
PI227331 |
2.5 |
X |
X |
PI229333 |
2.5 |
|
X |
PI238109 |
2.3 |
X |
|
PI240667A |
1 |
X |
|
PI258383 |
2 |
X |
|
PI291309C |
2 |
X |
|
PI341252 |
2.5 |
X |
X |
PI374189 |
2.3 |
X |
|
PI398335 |
2 |
X |
|
PI399070 |
2.5 |
X |
|
PI407831 |
2.5 |
X |
|
PI407833C |
2 |
|
X |
PI407845A |
2.5 |
X |
|
PI407858 |
2.3 |
X |
X |
PI407881 |
2.3 |
X |
|
PI408088 |
2.3 |
X |
|
PI408134B |
2 |
X |
|
PI408272B |
2 |
X |
|
PI417122 |
2.5 |
X |
|
PI417126 |
2.5 |
X |
|
PI417235 |
2 |
X |
|
PI417335 |
2.3 |
X |
|
PI423717 |
2 |
X |
|
PI423722 |
2.3 |
X |
|
PI423730B |
2.3 |
X |
|
PI423852 |
2.3 |
X |
X |
PI424190 |
2.5 |
X |
|
PI434973A |
2.5 |
X |
|
PI437110A |
2.3 |
X |
|
PI437437A |
1.5 |
|
X |
PI437740B |
2.3 |
X |
X |
PI437921 |
2 |
X |
|
PI437982 |
2.3 |
X |
X |
PI438073 |
2.3 |
X |
|
PI438371 |
2.5 |
X |
|
PI438480 |
2.5 |
X |
|
PI479735 |
2.3 |
X |
|
PI497965 |
2.5 |
X |
|
PI506737 |
2 |
X |
|
PI506863 |
2 |
X |
|
PI507142 |
2.5 |
|
X |
PI508269 |
2 |
X |
|
PI548325 |
2 |
X |
|
PI561289 |
2 |
X |
X |
PI561329 |
2.5 |
X |
|
PI561330A |
2 |
|
X |
PI561337 |
2 |
|
X |
PI561377 |
2.3 |
|
X |
PI566978 |
2.5 |
X |
|
PI567010B |
2.3 |
X |
|
PI567093B |
2 |
X |
X |
PI567104B |
2.5 |
X |
X |
PI567108B |
2.5 |
X |
X |
PI567129 |
2.3 |
X |
X |
PI567140B |
2.5 |
X |
|
PI567174C |
2.3 |
|
X |
PI567175C |
2 |
X |
X |
PI567300A |
2 |
X |
|
PI567409A |
2.3 |
X |
|
PI567470 |
2 |
X |
|
PI567473C |
2.5 |
X |
|
PI567474 |
2.3 |
X |
|
PI567489A |
2 |
X |
|
PI567507B |
2 |
X |
|
PI567554A |
2 |
X |
|
PI567560 |
2.5 |
X |
X |
PI567561 |
2.5 |
X |
|
PI567675 |
2.3 |
|
X |
PI567692 |
2 |
X |
X |
PI567718 |
2 |
X |
X |
PI567780A |
2.3 |
X |
|
PI578305B |
2.5 |
X |
|
PI587598A |
2.5 |
X |
|
PI587914B |
2 |
|
X |
PI587922A |
2 |
|
X |
PI587935A |
2.3 |
|
X |
PI588000 |
2.5 |
|
X |
PI588034 |
2.5 |
|
X |
PI592962B |
2.3 |
X |
|
PI594525 |
2.5 |
X |
X |
PI594538A |
2 |
X |
X |
PI594767B |
1 |
X |
|
PI597480A |
2.3 |
X |
|
PI603293B |
2.3 |
X |
|
PI603296 |
2.5 |
|
X |
PI603429D |
2.5 |
X |
|
PI603564A |
2.3 |
X |
|
PI603612 |
2.3 |
X |
X |
PI603704A |
2.5 |
X |
X |
PI605891B |
2.5 |
X |
|
PI628870 |
1.5 |
|
X |
PI628932 |
2.4 |
X |
|
Having illustrated and described the principles of the present invention, it should
be apparent to persons skilled in the art that the invention can be modified in arrangement
and detail without departing from such principles. We claim all modifications that
are within the spirit and scope of the appended claims.
All publications and published patent documents cited in this specification are incorporated
herein by reference to the same extent as if each individual publication or patent
application was specifically and individually indicated to be incorporated by reference.
A method for assaying a soybean plant for disease resistance, immunity, or susceptibility
comprising the steps of:
- a. detaching a plant tissue from said soybean plant;
- b. cultivating said tissue in a media;
- c. exposing said tissue to a plant pathogen; and
- d. assessing said tissue for resistance, immunity, or susceptibility to disease caused
by said pathogen.
The method as defined above further comprises:
e. isolating nucleic acids from said plant;
f. assaying said nucleic acids for the presence of one or more marker molecules for
a quantitative trait locus associated with said resistance, immunity, or susceptibility;
and
g. selecting said plant for use in a breeding program.
The method as defined above, wherein said tissue is a leaf, vascular tissue, flower,
pod, root, stem, seed, or a portion thereof.
The method as defined above, wherein said exposing said tissue to a plant pathogen
is accomplished by a means selected from the group consisting of (a) direct application
of the pathogen to the tissue; (b) inclusion of the pathogen in the culture media;
and (c) inclusion of an agent that is effectively contaminated with the pathogen and
serves to inoculate the tissue.
The method as defined above, wherein said plant pathogen exposure can be in the form
of pathogen macromolecules, cells, tissues, whole organism or combinations thereof,
wherein the pathogen, and parts thereof, is either living or dead so long that the
material mediates an immune response in the host tissue.
The method as defined above, wherein said disease resistance, immunity, or susceptibility
comprises a reaction to a pathogen selected from the group consisting of
Phakopsora pachyrhizi, Phakopsora meibomiae (Asian Soybean Rust),
Colletotrichum truncatum, Colletotrichum dematium var.
truncatum, Glomerella glycines (Soybean Anthracnose),
Phytophthora sojae (Phytophthora root and stem rot),
Sclerotinia sclerotiorum (Sclerotinia stem rot),
Fusarium solani f. sp.
glycines (sudden death syndrome),
Fusarium spp. (Fusarium root rot),
Macrophomina phaseolina (charcoal rot),
Septoria glycines, (Brown Spot),
Pythium aphanidermatum, Pythium debaryanum, Pythium irregulare, Pythium ultimum, Pythium
myriotylum, Pythium torulosum (Pythium seed decay),
Diaporthe phaseolorum var. sojae (Pod blight),
Phomopsis longicola (Stem blight),
Phomopsis spp. (Phomopsis seed decay),
Peronospora manshurica (Downy Mildew),
Rhizoctonia solani (Rhizoctonia root and stem rot,Rhizoctonia aerial blight),
Phialophora gregata (Brown Stem Rot),
Diaporthe phaseolorum var.
caulivora (Stem Canker),
Cercospora kikuchii (Purple Seed Stain),
Alternaria sp. (Target Spot),
Cercospora sojina (Frogeye Leafspot),
Sclerotium rolfsii (Southern blight),
Arkoola nigra (Black leaf blight),
Thielaviopsis basicola, (Black root rot),
Choanephora infundibulifera, Choanephora trispora (Choanephora leaf blight),
Leptosphaerulina trifolii (Leptosphaerulina leaf spot),
Mycoleptodiscus terrestris (Mycoleptodiscus root rot),
Neocosmospora vasinfecta (Neocosmospora stem rot),
Phyllosticta sojicola (Phyllosticta leaf spot),
Pyrenochaeta glycines (Pyrenochaeta leaf spot),
Cylindrocladium crotalariae (Red crown rot),
Dactuliochaeta glycines (Red leaf blotch),
Spaceloma glycines (Scab),
Stemphylium botryosum (Stemphylium leaf blight),
Corynespora cassiicola (Target spot),
Nematospora coryli (Yeast spot),
Phymatotrichum omnivorum (Cotton Root Rot),
Alfamovirus (Alfafa mosaic virus, AMV),
Comovirus (bean pod mottle virus, BPMV),
Potyvirus (bean yellow mosaic virus, BYMV), Bromovirus (cowpea chlorotic mottle virus, CCMV),
Begomovirus (mung bean yellow mosaivc virus, MYMV),
Potyvirus (peanut mottle virus, PeMoV),
Potyvirus (peanut stripe virus, PStV),
Cucumovirus (peanut stunt virus, PSV),
Caulimovirus (soybean chlorotic mottle virus, SbCMV),
Begomovirus (soybean crinkle leaf virus, SCLV),
Luteovirus (soybean dwarf virus, SbDV),
Potyvirus (soybean mosaic virus, SMV),
Nepovirus (soybean severe stunt virus, SSSV),
Nepovirus (tobacco ringspot virus, TRSV),
Bacillus subtilis (Bacillus seed decay),
Pseudomonas savastonoi pv.
glycinea (Bacterial blight),
Pseudomonas syringae subsp.
syringae (Bacterial crinkle-leaf),
Xanthomonas axonopodis pv.
glycines, (Bacterial pustule),
Curtobacterium flaccumfaciens pv.
flaccumfaciens, (Bacterial tan spot),
Curtobacterium flaccumfaciens pv.
flaccumfaciens, Ralstonia solanacearum, (Bacterial wilt),
Pseudomonas syringae pv.
tabaci (Wildfire),
Aphis glycines (Soybean aphid),
Heterodera glycines (Soybean cyst nematode),
Meloidogyne arenaria, Meloidogyne hapla, Meloidogyne incognita, Meloidogyne javanica (Root knot nematode),
Hoplolaimus Columbus, Hoplolaimus galeatus, Hoplolaimus magnistylus (Lance nematode),
Pratylenchus spp. (Lesion nematode),
Paratylenchus projectus, Paratylenchus tenuicaudatus (Pin nematode),
Rotylenchulus reniformis (Reniform nematode),
Criconemella ornata (Ring nematode),
Hemicycliophora spp. (Sheath nematode),
Heliocotylenchus spp. (Spiral nematode),
Belonolainus gracilis Belonolainus longicaudatus (Sting nematode),
Quinisulcius acutus, Tylenchorhynchus spp. (Stunt nematode) and
Paratrichodorus minor (Stubby root nematode). The method as defined above, wherein said tissue is assessed
for resistance, immunity, or susceptibility to
Phakopsora pachyrhizi, Phakopsora meibomiae (Asian Soybean Rust),
Colletotrichum truncatum, Colletotrichum dematium var.
truncatum, Glomerella glycines (Soybean Anthracnose),
Phytophthora sojae (Phytophthora root and stem rot),
Sclerotinia sclerotiorum (Sclerotinia stem rot),
Fusarium solani f. sp.
glycines (sudden death syndrome),
Fusarium spp. (Fusarium root rot),
Macrophomina phaseolina (charcoal rot),
Septoria glycines, (Brown Spot),
Pythium aphanidermatum, Pythium debaryanum, Pythium irregulare, Pythium ultimum, Pythium
myriotylum, Pythium torulosum (Pythium seed decay),
Diaporthe phaseolorum var. sojae (Pod blight),
Phomopsis longicola (Stem blight),
Phomopsis spp. (Phomopsis seed decay),
Peronospora manshurica (Downy Mildew),
Rhizoctonia solani (Rhizoctonia root and stem rot,Rhizoctonia aerial blight),
Phialophora gregata (Brown Stem Rot),
Diaporthe phaseolorum var.
caulivora (Stem Canker),
Cercospora kikuchii (Purple Seed Stain),
Alternaria sp. (Target Spot),
Cercospora sojina (Frogeye Leafspot),
Sclerotium rolfsii (Southern blight),
Arkoola nigra (Black leaf blight),
Thielaviopsis basicola, (Black root rot),
Choanephora infundibulifera, Choanephora trispora (Choanephora leaf blight),
Leptosphaerulina trifolii (Leptosphaerulina leaf spot),
Mycoleptodiscus terrestris (Mycoleptodiscus root rot),
Neocosmospora vasinfecta (Neocosmospora stem rot),
Phyllosticta sojicola (Phyllosticta leaf spot),
Pyrenochaeta glycines (Pyrenochaeta leaf spot),
Cylindrocladium crotalariae (Red crown rot),
Dactuliochaeta glycines (Red leaf blotch),
Spaceloma glycines (Scab),
Stemphylium botryosum (Stemphylium leaf blight),
Corynespora cassiicola (Target spot),
Nematospora coryli (Yeast spot),
Phymatotrichum omnivorum (Cotton Root Rot),
Alfamovirus (Alfafa mosaic virus, AMV),
Comovirus (bean pod mottle virus, BPMV),
Potyvirus (bean yellow mosaic virus, BYMV), Bromovirus (cowpea chlorotic mottle virus, CCMV),
Begomovirus (mung bean yellow mosaivc virus, MYMV),
Potyvirus (peanut mottle virus, PeMoV),
Potyvirus (peanut stripe virus, PStV),
Cucumovirus (peanut stunt virus, PSV),
Caulimovirus (soybean chlorotic mottle virus, SbCMV),
Begomovirus (soybean crinkle leaf virus, SCLV),
Luteovirus (soybean dwarf virus, SbDV),
Potyvirus (soybean mosaic virus, SMV),
Nepovirus (soybean severe stunt virus, SSSV),
Nepovirus (tobacco ringspot virus, TRSV),
Bacillus subtilis (Bacillus seed decay),
Pseudomonas savastonoi pv.
glycinea (Bacterial blight),
Pseudomonas syringae subsp.
syringae (Bacterial crinkle-leaf),
Xanthomonas axonopodis pv.
glycines, (Bacterial pustule),
Curtobacterium flaccumfaciens pv.
flaccumfaciens, (Bacterial tan spot),
Curtobacterium flaccumfaciens pv.
flaccumfaciens, Ralstonia solanacearum, (Bacterial wilt),
Pseudomonas syringae pv.
tabaci (Wildfire),
Aphis glycines (Soybean aphid),
Heterodera glycines (Soybean cyst nematode),
Meloidogyne arenaria, Meloidogyne hapla, Meloidogyne incognita, Meloidogyne javanica (Root knot nematode),
Hoplolaimus Columbus, Hoplolaimus galeatus, Hoplolaimus magnistylus (Lance nematode),
Pratylenchus spp. (Lesion nematode),
Paratylenchus projectus, Paratylenchus tenuicaudatus (Pin nematode),
Rotylenchulus reniformis (Reniform nematode),
Criconemella ornata (Ring nematode),
Hemicycliophora spp. (Sheath nematode),
Heliocotylenchus spp. (Spiral nematode),
Belonolainus gracilis, Belonolainus longicaudatus (Sting nematode),
Quinisulcius acutus, Tylenchorhynchus spp. (Stunt nematode) and
Paratrichodorus minor (Stubby root nematode). The method as defined above, wherein said selected soybean
plant is selected from the group consisting of
Glycine arenaria, Glycine argyrea, Glycine canescens, Glycine clandestine, Glycine
curvata, Glycine cyrtoloba, Glycine falcate, Glycine latifolia, Glycine latrobeana,
Glycine max, Glycine microphylla, Glycine pescadrensis, Glycine pindanica, Glycine
rubiginosa, Glycine soja, Glycine sp., Glycine stenophita, Glycine tabacina and
Glycine tomentella.
The method as defined above, wherein said media comprises water and nutrients necessary
to sustain infection, while not interfering with the effect of said disease resistance
quantitative trait loci.
The method as defined above, wherein said disease resistance, immunity, or susceptibility
is selected from the group consisting of
Phytophthora (root rot) infection tolerance, resistance to
Fusarium solani f. sp.
glycines (sudden death syndrome),
Cercospora sojina (Frogeye leaf spot),
Phialophora gegata (brown stem rot),
Sclerotinia (stem rot), and Asian Soybean Rust (ASR) resistance.
The method as defined above, wherein said quantitative trait locus is selected from
the group consisting of ASR resistance loci 1-13.
The method as defined above, wherein said soybean plant is a progeny from a cross
between a soybean plant comprising a desirable disease resistance quantitative trait
locus and a soybean plant of an elite line.
A soybean plant selected using the method as defined above.
An isolated or recombinant DNA molecule selected from the group consisting of SEQ
ID NOs: 67 through 99.
A method for selecting an ASR resistant soybean plant comprising the steps of:
- a) isolating nucleic acids from a plurality of soybean plants;
- b) detecting in said isolated nucleic acids the presence of one or more marker molecules
associated with ASR resistance locus 1, wherein said marker molecule is selected from
the group consisting of NS0093250, NS0119710, NS0103004, NS0099454, NS0102630, NS0102915,
NS0102913, NS0123728, NS0129943, NS0102168, NS0092723, NS0098177, NS0127343, NS0101121,
and any marker molecule mapped within 10 centimorgans or less from said marker molecules;
and c) selecting a soybean plant comprising said one or more marker molecules, thereby
selecting an ASR resistant soybean plant.
A method for selecting an ASR resistant soybean plant comprising the steps of:
- a) isolating nucleic acids from a plurality of soybean plants;
- b) detecting in said isolated nucleic acids the presence of one or more marker molecules
associated with ASR resistance locus 3, wherein said marker molecule is selected from
the group consisting of NS0099746, NS0123747, NS0126598, NS0128378, NS0096829, NS0125408,
NS0098902, NS0099529, NS0097798, NS0137477, NS0095322, NS0136101, NS0098982, and any
marker molecule mapped within 10 centimorgans or less from said marker molecules;
and
- c) selecting a soybean plant comprising said one or more marker molecules, thereby
selecting an ASR resistant soybean plant.
A method for selecting an ASR resistant soybean plant comprising the steps of:
- a) isolating nucleic acids from a plurality of soybean plants;
- b) detecting in said isolated nucleic acids the presence of one or more marker molecules
associated with ASR resistance loci 5-9, wherein said marker molecule is selected
from the group consisting of NS0103033 and any one marker molecule mapped within 10
centimorgans or less from said marker molecules; and
- c) selecting a soybean plant comprising said one or more marker molecules, thereby
selecting an ASR resistant soybean plant.
A method for selecting an ASR resistant soybean plant comprising the steps of:
- a) isolating nucleic acids from a plurality of soybean plants;
- b) detecting in said isolated nucleic acids the presence of one or more marker molecules
associated with ASR resistance loci 10-13, wherein said marker molecule is selected
from the group consisting of NS0124935 and any one marker molecule mapped within 10
centimorgans or less from said marker molecules; and
- c) selecting a soybean plant comprising said one or more marker molecules, thereby
selecting an ASR resistant soybean plant.
A method for selecting an ASR resistant soybean plant comprising the steps of:
- a) isolating nucleic acids from a plurality of soybean plants;
- b) detecting in said isolated nucleic acids the presence of one or more marker molecules
associated with ASR resistance locus 2, wherein said marker molecules are selected
from a region corresponding to linkage group J or N; and
- c) selecting a soybean plant comprising said one or more marker molecules, thereby
selecting an ASR resistant soybean plant.
A method for selecting an ASR resistant soybean plant comprising the steps of:
- a) isolating nucleic acids from a plurality of soybean plants;
- b) detecting in said isolated nucleic acids the presence of one or more marker molecules
associated with ASR resistance locus 4, wherein said marker molecules are selected
from a region corresponding to linkage group N; and
- c) selecting a soybean plant comprising said one or more marker molecules, thereby
selecting an ASR resistant soybean plant.
An ASR resistant soybean plant selected using any one of the methods as defined above.
A soybean plant comprising at least one introgressed ASR resistance locus selected
from the group consisting of ASR resistance loci 5-13.
The soybean plant as defined above, wherein said introgressed ASR resistance locus
originates from soybean accessions listed in Table 6.
The soybean plant as defined above further comprising one or more ASR resistance locus
selected from the group consisting of ASR resistance loci 1-4.
The soybean plant as defined above, wherein said ASR resistance loci 1-4 originates
from soybean accessions listed in Table 4.
A soybean plant comprising an introgressed quantitative trait locus, wherein said
locus originates from soybean accession PI 200487 and wherein said locus confers a
slow rust phenotype.
